Tuesday, May 12, 2009


Six Steps to Mushroom Farming

The Pennsylvania State University, College of Agriculture, Extension Service,University Park, Pennsylvania

Mushroom farming consists of six steps, and although the divisions are somewhat arbitrary, these steps identify what is needed to form a production system.
The six steps are Phase I composting, Phase II composting, spawning, casing, pinning, and cropping. These steps are described in their naturally occurring sequence, emphasizing the salient features within each step. Compost provides nutrients needed for mushrooms to grow. Two types of material are generally used for mushroom compost, the most used and least expensive being wheat straw-bedded horse manure. Synthetic compost is usually made from hay and crushed corncobs, although the term often refers to any mushroom compost where the prime ingredient is not horse manure. Both types of compost require the addition of nitrogen supplements and a conditioning agent, gypsum.
The preparation of compost occurs in two steps referred to as Phase I and Phase II composting. The discussion of compost preparation and mushroom production begins with Phase I composting.
Phase I: Making Mushroom Compost

This phase of compost preparation usually occurs outdoors although an enclosed building or a structure with a roof over it may be used. A concrete slab, referred to as a wharf, is required for composting. In addition, a compost turner to aerate and water the ingredients, and a tractor-loader to move the ingredients to the turner is needed. In earlier days piles were turned by hand using pitchforks, which is still an alternative to mechanized equipment, but it is labor intensive and physically demanding.
Phase I composting is initiated by mixing and wetting the ingredients as they are stacked in a rectangular pile with tight sides and a loose center. Normally, the bulk ingredients are put through a compost turner. Water is sprayed onto the horse manure or synthetic compost as these materials move through the turner. Nitrogen supplements and gypsum are spread over the top of the bulk ingredients and are thoroughly mixed by the turner. Once the pile is wetted and formed, aerobic fermentation (composting) commences as a result of the growth and reproduction of microorganisms, which occur naturally in the bulk ingredients. Heat, ammonia, and carbon dioxide are released as by-products during this process. Compost activators, other than those mentioned, are not needed, although some organic farming books stress the need for an "activator."
Mushroom compost develops as the chemical nature of the raw ingredients is converted by the activity of microorganisms, heat, and some heat-releasing chemical reactions. These events result in a food source most suited for the growth of the mushroom to the exclusion of other fungi and bacteria. There must be adequate moisture, oxygen, nitrogen, and carbohydrates present throughout the process, or else the process will stop. This is why water and supplements are added periodically, and the compost pile is aerated as it moves through the turner.
Gypsum is added to minimize the greasiness compost normally tends to have. Gypsum increases the flocculation of certain chemicals in the compost, and they adhere to straw or hay rather than filling the pores (holes) between the straws. A side benefit of this phenomenon is that air can permeate the pile more readily, and air is essential to the composting process. The exclusion of air results in an airless (anaerobic) environment in which deleterious chemical compounds are formed which detract from the selectivity of mushroom compost for growing mushrooms. Gypsum is added at the outset of composting at 40 lbs. per ton of dry ingredients.
Nitrogen supplements in general use today include brewerâs grain, seed meals of soybeans, peanuts, or cotton, and chicken manure, among others. The purpose of these supplements is to increase the nitrogen content to 1.5 percent for horse manure or 1.7 percent for synthetic, both computed on a dry weight basis. Synthetic compost requires the addition of ammonium nitrate or urea at the outset of composting to provide the compost microflora with a readily available form of nitrogen for their growth and reproduction.
Corn cobs are sometimes unavailable or available at a price considered to be excessive. Substitutes for or complements to corn cobs include shredded hardwood bark, cottonseed hulls, neutralized grape pomace, and cocoa bean hulls. Management of a compost pile containing any one of these materials is unique in the requirements for watering and the interval between turning.
The initial compost pile should be 5 to 6 feet wide, 5 to 6 feet high, and as long as necessary. A two-sided box can be used to form the pile (rick), although some turners are equipped with a "ricker" so a box isnât needed. The sides of the pile should be firm and dense, yet the center must remain loose throughout Phase I composting. As the straw or hay softens during composting, the materials become less rigid and compactions can easily occur. If the materials become too compact, air cannot move through the pile and an anaerobic environment will develop.
Turning and watering are done at approximately 2-day intervals, but not unless the pile is hot (145° to 170°F). Turning provides the opportunity to water, aerate, and mix the ingredients, as well as to relocate the straw or hay from a cooler to a warmer area in the pile, outside versus inside. Supplements are also added when the ricks are turned, but they should be added early in the composting process. The number of turnings and the time between turnings depends on the condition of the starting material and the time necessary for the compost to heat to temperatures above 145°F.
Water addition is critical since too much will exclude oxygen by occupying the pore space, and too little can limit the growth of bacteria and fungi. As a general rule, water is added up to the point of leaching when the pile is formed and at the time of first turning, and thereafter either none or only a little is added for the duration of composting. On the last turning before Phase II composting, water can be applied generously so that when the compost is tightly squeezed, water drips from it. There is a link between water, nutritive value, microbial activity, and temperature, and because it is a chain, when one condition is limiting for one factor, the whole chain will cease to function. Biologists see this phenomenon repeatedly and have termed it the Law of Limiting Factors.
Phase I composting lasts from 7 to 14 days, depending on the nature of the material at the start and its characteristics at each turn. There is a strong ammonia odor associated with composting, which is usually complemented by a sweet, moldy smell. When compost temperatures are 155°F and higher, and ammonia is present, chemical changes occur which result in a food rather exclusively used by the mushrooms. As a by-product of the chemical changes, heat is released and the compost temperatures increase. Temperatures in the compost can reach 170° to 180°F during the second and third turnings when a desirable level of biological and chemical activity is occurring. At the end of Phase I the compost should: a) have a chocolate brown color; b) have soft, pliable straws, c) have a moisture content of from 68 to 74 percent; and d) have a strong smell of ammonia. When the moisture, temperature, color, and odor described have been reached, Phase I composting is completed.

Phase II: Finishing the Compost

There are two major purposes to Phase II composting. Pasteurization is necessary to kill any insects, nematodes, pest fungi, or other pests that may be present in the compost. And second, it is necessary to remove the ammonia which formed during Phase I composting. Ammonia at the end of Phase II in a concentration higher than 0.07 percent is often lethal to mushroom spawn growth, thus it must be removed; generally, a person can smell ammonia when the concentration is above 0.10 percent.
Phase II takes place in one of three places, depending on the type of production system used. For the zoned system of growing, compost is packed into wooden trays, the trays are stacked six to eight high, and are moved into an environmentally controlled Phase II room. Thereafter, the trays are moved to special rooms, each designed to provide the optimum environment for each step of the mushroom growing process. With a bed or shelf system, the compost is placed directly in the beds, which are in the room used for all steps of the crop culture. The most recently introduced system, the bulk system, is one in which the compost is placed in a cement-block bin with a perforated floor and no cover on top of the compost; this is a room specifically designed for Phase II composting.
The compost, whether placed in beds, trays, or bulk, should be filled uniformly in depth and density or compression. Compost density should allow for gas exchange, since ammonia and carbon dioxide will be replaced by outside air.
Phase II composting can be viewed as a controlled, temperature-dependent, ecological process using air to maintain the compost in a temperature range best suited for the de-ammonifying organisms to grow and reproduce. The growth of these thermophilic (heat-loving) organisms depends on the availability of usable carbohydrates and nitrogen, some of the nitrogen in the form of ammonia.
Optimum management for Phase II is difficult to define and most commercial growers tend toward one of the two systems in general use today: high temperature or low temperature.
A high temperature Phase II system involves an initial pasteurization period during which the compost and the air temperature are raised to at least 145°F for 6 hours. This can be accomplished by heat generated during the growth of naturally occurring microorganisms or by injecting steam into the room where the compost has been placed, or both. After pasteurization, the compost is re-conditioned by immediately lowering the temperature to 140°F by flushing the room with fresh air. Thereafter, the compost is allowed to cool gradually at a rate of approximately 2° to 3°F each day until all the ammonia is dissipated. This Phase II system requires approximately 10 to 14 days to complete.
In the low temperature Phase II system the compost temperature is initially increased to about 126°F with steam or by the heat released via microbial growth, after which the air temperature is lowered so the compost is in a temperature range of 125° to 130°F range. During the 4 to 5 days after pasteurization, the compost temperature may be lowered by about 2°F a day until the ammonia is dissipated.
It is important to remember the purposes of Phase II when trying to determine the proper procedure and sequence to follow. One purpose is to remove unwanted ammonia. To this end the temperature range from 125° to 130°F is most efficient since de-ammonifying organisms grow well in this temperature range. A second purpose of Phase II is to remove any pests present in the compost by use of a pasteurization sequence.
At the end of Phase II the compost temperature must be lowered to approximately 75° to 80°F before spawning (planting) can begin. The nitrogen content of the compost should be 2.0 to 2.4 percent, and the moisture content between 68 and 72 percent. Also, at the end of Phase II it is desirable to have 5 to 7 lbs. of dry compost per square foot of bed or tray surface to obtain profitable mushroom yields. It is important to have both the compost and the compost temperatures uniform during the Phase II process since it is desirable to have as homogenous a material as possible.

Phase III: Spawning

Mushroom compost must be inoculated with mushroom spawn (Latin expandere = to spread out) if one expects mushrooms to grow. The mushroom itself is the fruit of a plant as tomatoes are of tomato plants. Within the tomato one finds seeds, and these are used to start the next season's crop. Microscopic spores form within a mushroom cap, but their small size precludes handling them like seeds. As the tomato comes from a plant with roots, stems, and leaves, the mushroom arises from thin, thread-like cells called mycelium. Fungus mycelium is the white, thread-like plant often seen on rotting wood or moldy bread. Mycelium can be propagated vegetatively, like separating daffodil bulbs and getting more daffodil plants. Specialized facilities are required to propagate mycelium, so the mushroom mycelium does not get mixed with the mycelium of other fungi. Mycelium propagated vegetatively is known as spawn, and commercial mushroom farmers purchase spawn from any of about a dozen spawn companies.
Spawn makers start the spawn-making process by sterilizing a mixture of rye grain plus water and chalk; wheat, millet, and other small grain may be substituted for rye. Sterilized horse manure formed into blocks was used as the growth medium for spawn up to about 1940, and this was called block or brick spawn, or manure spawn; such spawn is uncommon now. Once sterilized grain has a bit of mycelium added to it, the grain and mycelium is shaken 3 times at 4-day intervals over a 14-day period of active mycelial growth. Once the grain is colonized by the mycelium, the product is called spawn. Spawn can be refrigerated for a few months, so spawn is made in advance of a farmerâs order for spawn.
In the United States, mushroom growers have a choice of four major mushroom cultivars: a) Smooth white - cap smooth, cap and stalk white; b) Off-white - cap scaly with stalk and cap white; c) Cream - cap smooth to scaly with stalk white and cap white to cream; and d) Brown - cap smooth, cap chocolate brown with a white stalk. Within each of the four major groups, there are various isolates, so a grower may have a choice of up to eight smooth white strains. The isolates vary in flavor, texture, and cultural requirements, but they are all mushrooms. Generally, white and off-white cultivars are used for processed foods like soups and sauces, but all isolates are good eating as fresh mushrooms.
Spawn is distributed on the compost and then thoroughly mixed into the compost. For years this was done by hand, broadcasting the spawn over the surface of the compost and ruffling it in with a small rake-like tool. In recent years, however, for the bed system, spawn is mixed into the compost by a special spawning machine which mixes the compost and spawn with tines or small finger-like devices. In a tray or batch system, spawn is mixed into the compost as it moves along a conveyer belt or while falling from a conveyor into a tray. The spawning rate is expressed as a unit or quart per so many square feet of bed surface; 1 unit per 10 ft is desirable. The rate is sometimes expressed on the basis of spawn weight versus compost weight; a 2 percent spawning rate is desirable.
Once the spawn has been mixed throughout the compost and the compost worked so the surface is level, the compost temperature is maintained at 75°F and the relative humidity is kept high to minimize drying of the compost surface or the spawn. Under these conditions the spawn will grow - producing a thread-like network of mycelium throughout the compost. The mycelium grows in all directions from a spawn grain, and eventually the mycelium from the different spawn grains fuse together, making a spawned bed of compost one biological entity. The spawn appears as a white to blue-white mass throughout the compost after fusion has occurred. As the spawn grows it generates heat, and if the compost temperature increases to above 80° to 85°F, depending on the cultivar, the heat may kill or damage the mycelium and eliminate the possibility of maximum crop productivity and/or mushroom quality. At temperatures below 74°F, spawn growth is slowed and the time interval between spawning and harvesting is extended.
The time needed for spawn to colonize the compost depends on the spawning rate and its distribution, the compost moisture and temperature, and the nature or quality of the compost. A complete spawn run usually requires 14 to 21 days. Once the compost is fully grown with spawn, the next step in production is at hand.

Phase IV: Casing

Casing is a top-dressing applied to the spawn-run compost on which the mushrooms eventually form. Clay-loam field soil, a mixture of peat moss with ground limestone, or reclaimed weathered, spent compost can be used as casing. Casing does not need nutrients since casing act as a water reservoir and a place where rhizomorphs form. Rhizomorphs look like thick strings and form when the very fine mycelium fuses together. Mushroom initials, primordia, or pins form on the rhizomorphs, so without rhizomorphs there will be no mushrooms. Casing should be pasteurized to eliminate any insects and pathogens it may be carrying. Also, it is important that the casing be distributed so the depth is uniform over the surface of the compost. Such uniformity allows the spawn to move into and through the casing at the same rate and, ultimately, for mushrooms to develop at the same time. Casing should be able to hold moisture since moisture is essential for the development of a firm mushroom.
Managing the crop after casing requires that the compost temperature be kept at around 75°F for up to 5 days after casing, and the relative humidity should be high. Thereafter, the compost temperature should be lowered about 2°F each day until small mushroom initials (pins) have formed. Throughout the period following casing, water must be applied intermittently to raise the moisture level to field capacity before the mushroom pins form. Knowing when, how, and how much water to apply to casing is an "art form" which readily separates experienced growers from beginners.

Phase V: Pinning

Mushroom initials develop after rhizomorphs have formed in the casing. The initials are extremely small but can be seen as outgrowths on a rhizomorph. Once an initial quadruples in size, the structure is a pin. Pins continue to expand and grow larger through the button stage, and ultimately a button enlarges to a mushroom. Harvestable mushrooms appear 18 to 21 days after casing. Pins develop when the carbon dioxide content of room air is lowered to 0.08 percent or lower, depending on the cultivar, by introducing fresh air into the growing room. Outside air has a carbon dioxide content of about 0.04 percent.
The timing of fresh air introduction is very important and is something learned only through experience. Generally, it is best to ventilate as little as possible until the mycelium has begun to show at the surface of the casing, and to stop watering at the time when pin initials are forming. If the carbon dioxide is lowered too early by airing too soon, the mycelium stops growing through the casing and mushroom initials form below the surface of the casing. As such mushrooms continue to grow, they push through the casing and are dirty at harvest time. Too little moisture can also result in mushrooms forming below the surface of the casing. Pinning affects both the potential yield and quality of a crop and is a significant step in the production cycle.

Phase VI: Cropping

The terms flush, break, or bloom are names given to the repeating 3- to 5-day harvest periods during the cropping cycle; these are followed by a few days when no mushrooms are available to harvest. This cycle repeats itself in a rhythmic fashion, and harvesting can go on as long as mushrooms continue to mature. Most mushroom farmers harvest for 35 to 42 days, although some harvest a crop for 60 days, and harvest can go on for as long as 150 days.
Air temperature during cropping should be held between 57° to 62°F for good results. This temperature range not only favors mushroom growth, but cooler temperatures can lengthen the life cycles of both disease pathogens and insects pests. It may seem odd that there are pests which can damage mushrooms, but no crop is grown that does not have to compete with other organisms. Mushroom pests can cause total crop failures, and often the deciding factor on how long to harvest a crop is based on the level of pest infestation. These pathogens and insects can be controlled by cultural practices coupled with the use of pesticides, but it is most desirable to exclude these organisms from the growing rooms.
The relative humidity in the growing rooms should be high enough to minimize the drying of casing but not so high as to cause the cap surfaces of developing mushrooms to be clammy or sticky. Water is applied to the casing so water stress does not hinder the developing mushrooms; in commercial practice this means watering 2 to 3 times each week. Each watering may consist of more or fewer gallons, depending on the dryness of the casing, the cultivar being grown, and the stage of development of the pins, buttons, or mushrooms. Most first-time growers apply too much water and the surface of the casing seals; this is seen as a loss of texture at the surface of the casing. Sealed casing prevents the exchange of gases essential for mushroom pin formation. One can estimate how much water to add after first break has been harvested by realizing that 90 percent of the mushroom is water and a gallon of water weight 8.3 lbs. If 100 lbs. of mushrooms were harvested, 90 lbs. of water (11 gal.) were removed from the casing; and this is what must be replaced before second break mushrooms develop.
Outside air is used to control both the air and compost temperatures during the harvest period. Outside air also displaces the carbon dioxide given off by the growing mycelium. The more mycelial growth, the more carbon dioxide produced, and since more growth occurs early in the crop, more fresh air is needed during the first two breaks. The amount of fresh air also depends on the growing mushrooms, the area of the producing surface, the amount of compost in the growing room, and the condition or composition of the fresh air being introduced. Experience seems to be the best guide regarding the volume of air required, but there is a rule of thumb: 0.3ft/hr when the compost is 8 inches deep, and of this volume 50 to 100 percent must be outside air.
A question frequently arises concerning the need for illumination while the mushrooms grow. Mushrooms do not require light to grow, only green plants require light for photosynthesis. Growing rooms can be illuminated to facilitate harvesting or cropping practices, but it is more common for workers or mushroom farmers to be furnished with minerâs lamps rather than illuminating an entire room.
Ventilation is essential for mushroom growing, and it is also necessary to control humidity and temperature. Moisture can be added to the air by a cold mist or by live steam, or simply by wetting the walls and floors. Moisture can be removed from the growing room by: 1) admitting a greater volume of outside air; 2) introducing drier air; 3) moving the same amount of outside air and heating it to a higher temperature since warmer air holds more moisture and thus lowers the relative humidity. Temperature control in a mushroom growing room is no different from temperature control in your home. Heat can originate from hot water circulated through pipes mounted on the walls. Hot, forced air can be blown through a ventilation duct, which is rather common at more recently built mushroom farms. There are a few mushroom farms located in limestone caves where the rock acts as both a heating and cooling surface depending on the time of year. Caves of any sort are not necessarily suited for mushroom growing, and abandoned coal mines have too many intrinsic problems to be considered as viable sites for a mushroom farm. Even limestone caves require extensive renovation and improvement before they are suitable for mushroom growing, and only the growing occurs in the cave with composting taking place above ground on a wharf.
Mushrooms are harvested in a 7- to 10-day cycle, but this may be longer or shorter depending on the temperature, humidity, cultivar, and the stage when they are picked. When mature mushrooms are picked, an inhibitor to mushroom development is removed and the next flush moves toward maturity. Mushrooms are normally picked at a time when the veil is not too far extended. Consumers in North America want closed, tight, mushrooms while in England and Australia open, flat mushrooms are desired. The maturity of a mushroom is assessed by how far the veil is stretched, and not by how large the mushroom is. Consequently, mature mushrooms are both large and small, although farmers and consumers alike prefer medium- to large-size mushrooms.
Picking and packaging methods often vary from farm to farm. Freshly harvested mushrooms must be kept refrigerated at 35° to 45°F. To prolong the shelf life of mushrooms, it is important that mushrooms "breathe" after harvest, so storage in a nonwaxed paper bag is preferred to a plastic bag.
After the last flush of mushrooms has been picked, the growing room should be closed off and the room pasteurized with steam. This final pasteurization is designed to destroy any pests which may be present in the crop or the woodwork in the growing room, thus minimizing the likelihood of infesting the next crop.
It takes approximately 15 weeks to complete an entire production cycle, from the start of composting to the final steaming off after harvesting has ended. For this work a mushroom grower can expect anywhere from 0 to 4 lbs. per square foot; the national average for 1980 was 3.12 lbs. per square foot. Final yield depends on how well a grower has monitored and controlled the temperature, humidity, pests, and so on. All things considered, the most important factors for good production appear to be experience plus an intuitive feel for the biological rhythms of the commercial mushroom. The production system used to grow a crop can be chosen after the basics of mushroom growing is understood.
Related Readings

Atkins, Fred C. 1974. Guide to Mushroom Growing. Faber and Faber Ltd., 3 Queen Square, London.
Blum, H. 1977. The Mushroom Industry in Ontario. Economic Branch, Ontario Ministry of Agriculture and Food, Toronto, Ontario.
Chang, S.T. and W. A. Hayes. 1978. The Biology and Cultivation of Edible Mushrooms. Academic Press, New York.
Lambert, L. F. 1958. Practical and Scientific Mushroom Culture. L. F. Lambert, Inc. Coatesville, PA 19230.
Swayne, J. B. 1950. Handbook of Mushroom Culture, Kennett Square, PA 19348.
Vedder, P. J. C. 1978. Modern Mushroom Growing. Pitman Press, Bath, G. B. Distributed in U.S.A. by S.A.S., Inc., RFD 1, Box 80 A, Madisonville, TX 77864.

Tuesday, May 5, 2009

Mushroom Cultivation and Marketing

Horticulture Production Guide


Gray Oyster Mushrooms
Gray Oyster Mushrooms
Glen Babcock
Garden City Fungi

The market for mushrooms continues to grow due to interest in their culinary, nutritional, and health benefits. They also show potential for use in waste management. However, as fungi, mushrooms have life cycles very different from those of green plants. The choice of species to raise depends both on the growth media available and on market considerations. Oyster mushrooms, which grow on many substrates, are easiest for a beginner. Shiitake mushrooms already have earned considerable consumer demand. Only two mycorrhizal mushrooms, morels and truffles, have been commercially cultivated. Mushroom cultivation offers benefits to market gardens when it is integrated into the existing production system. A careful analysis of potential markets must be the first step in deciding whether to raise mushrooms to sell. Many information resources are available for further research.

Table of Contents


Small-scale mushroom production represents an opportunity for farmers interested in an additional enterprise and is a specialty option for farmers without much land. This publication is designed for market gardeners who want to incorporate mushrooms into their systems and for those farmers who want to use mushroom cultivation as a way to extract value from woodlot thinnings and other "waste" materials. Mushroom production can play an important role in managing farm organic wastes when agricultural and food processing by-products are used as growing media for edible fungi. The spent substrate can then be composted and applied directly back to the soil. This publication includes resources for entrepreneurs who wish to do further research.

Many people are intrigued by mushrooms nutritional and medicinal properties, in addition to their culinary appeal. Mushrooms contain many essential amino acids; white button mushrooms, for example, contain more protein than kidney beans. Shiitake mushrooms are less nutritious, but are still a good source of protein.(Royse and Schisler, 1980) As a group, mushrooms also contain some unsaturated fatty acids, provide several of the B vitamins, and vitamin D. Some even contain significant vitamin C, as well as the minerals potassium, phosphorus, calcium, and magnesium.(Park, 2001)

Asian traditions maintain that some specialty mushrooms provide health benefits. Chinese doctors use at least 50 species. Two recent books, Medicinal Mushrooms: An Exploration of Tradition, Healing and Culture and Medicinal Mushrooms You Can Grow, detail existing research on the health benefits of mushrooms. See the Resources section at the end of this guide for specifics on these books and other sources of information

Producing nutritious food at a profit, while using materials that would otherwise be considered "waste," constitutes a valuable service in the self-sustaining community we might envision for the future.

Mushroom production is labor- and management-intensive. Specialty mushrooms are not a "get rich quick" enterprise. On the contrary, it takes a considerable amount of knowledge, research, planning, and capital investment to set up a production system. You must also be prepared to face sporadic fruiting, invasions of "weed" fungi, insect pests, and unreliable market prices.

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Growing Mushrooms

Mushroom production is completely different from growing green plants. Mushrooms do not contain chlorophyll and therefore depend on other plant material (the "substrate") for their food. The part of the organism that we see and call a mushroom is really just the fruiting body. Unseen is the mycelium—tiny threads that grow throughout the substrate and collect nutrients by breaking down the organic material. This is the main body of the mushroom. Generally, each mushroom species prefers a particular growing medium, although some species can grow on a wide range of materials.

If you are considering mushroom production, become thoroughly familiar with the life cycles of fungi. A very general description is included below. A plant pathology textbook is a good resource for learning more about these complex life cycles.

Once you are familiar with the various fungi life cycles, learn the growth requirements of each of the species you are considering. Two basic references are The Mushroom Cultivator, by Stamets and Chilton, and the aforementioned Growing Gourmet and Medicinal Mushrooms by Stamets (See Resources).

Growing mushrooms outdoors as a part of a market garden involves little effort after you have inoculated the logs or other substrate with the mushroom spawn. Your duties are mainly to maintain humidity and monitor for fruiting. When mushrooms appear, you add them to your other garden products and sell them. (See Mushrooms on the Farm and in the Garden, below.)

Most available markets, however, require more mushrooms than occasional fruiting provides. Indoor production can fill the gaps when outside fruiting lags. The entire operation can also be conducted inside. However, indoor mushroom production demands a much higher level of knowledge, continuous monitoring, and timely manipulation of environmental conditions.

These are the steps in mushroom production—a cycle that takes about 15 weeks (time varies by species) from start to finish.

  • Choosing a growing medium
  • Pasteurizing or sterilizing the medium
  • Seeding the beds with spawn (material from mature mushrooms grown on sterile media)
  • Maintaining optimal temperature, moisture, and other conditions for mycelium growth and the conditions that favor fruiting (This is the most challenging step.)
  • Harvesting, packaging, and selling the mushrooms
  • Cleaning the facility and beginning again (Cooner, 2001)
The mushroom culture diagram
© 1995 by Paul Stamets
Reprinted with Permission

The substrate on which the mushrooms will fruit must be sterilized or pasteurized in order to destroy any fungal and/or bacterial competitors. Low-tech substrate preparation methods are described in the books by Paul Stamets and by Peter Oei (see Resources).

To produce spawn, you inoculate a pasteurized medium, usually grain, with the sterile culture of a particular mushroom species. After the culture has grown throughout the medium, it is called spawn. Producing spawn requires exacting laboratory procedures. Terri Marie Beauséjour, cultivation chair for the Mycological Society of San Francisco, has written an excellent article that can help the beginner who is put off by the technical aspects of mushroom cultivation. Titled "Getting Started with Mushroom Cultivation: The Wisdom of Simplicity," it is available on the Web at www.mykoweb.com/articles/cultivation.html.

Many mushroom suppliers sell several kinds of spawn, and the beginning mushroom farmer should take advantage of this selection in early trials to determine which species grow best on available materials. Eventually, learning to produce spawn might reduce your cost of production. Evaluate this possibility only after you have mastered the later stages of cultivation.

While the mycelium is growing—and until it fully occupies the substrate—the mushroom farmer typically manipulates the growing environment to favor mycelial growth. The atmospheric conditions are then changed to initiate "pinheads," and then to complete fruiting. For example, in oyster mushroom production under closely controlled conditions, the grower lowers the temperature and the CO2 in the grow room to initiate fruiting. Each species has specific requirements for its stages of development. The Mushroom Cultivator provides detailed information on the requirements for 16 species.(Stamets & Chilton, 1983)

When you can cut the time between harvests, annual production increases. Short cycles are what the large-scale commercial producers aim for, constantly looking for ways to increase efficiency. This is the competition you face if you plan to sell your product on the wholesale market.

Paul Stamets of Fungi Perfecti, an educational and mushroom supply company
(See Resources), has spent most of his life studying the growth and cultivation of fungi. His book Growing Gourmet & Medicinal Mushrooms (see Resources) is an invaluable resource for anyone considering the cultivation of any mushroom species. He describes several alternative methods of producing mushrooms, including growing them outdoors on logs, on stumps, and in the garden, as well as indoors in bags or on columns.

Peter Oei, in Manual on Mushroom Cultivation (see Resources), describes in some detail how alternative mushroom production systems have been used successfully in developing countries. Many ideas for low-input systems are included. In practice, it is unlikely that the beginner can successfully compete in the wholesale market against highly capitalized and efficient mushroom companies. A better choice for the beginner is to develop a niche market for high-quality fresh mushrooms, then sell them at retail, or to produce a value-added mushroom product, such as a soup mix or sauce.

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Mushrooms on the Farm and in the Garden

Fungi cycle nutrients that nourish new life in the soil. Recognizing this essential function, inventive gardeners integrate mushrooms into farm, garden, and permaculture systems. Mushrooms can also be grown in lawns, polytunnels, vegetable gardens, and woodlands.(Edwards, 2000)

Terri Marie Beauséjour, a writer for Mushroom the Journal, encourages creativity and imagination when planting mushrooms in a garden. Look at the "fungamentals," she writes, the necessities such as available substrates, microhabitats, sun, shade, wind, and humidity conditions. Gardens offer ample substrates—organic waste materials—while plants provide shade and humidity. Plug-inoculated blocks buried among plantings work well for oyster and Stropharia rugoso-annulata mushrooms. Beauséjour suggests using a misting sprinkler for mushrooms in gardens.(Beauséjour, 1999)

Grower and author Ken Litchfield notes that mulching, a standard gardening practice, not only regulates soil temperature and humidity but also nourishes fungi. He also suggests surrounding raised beds with partially buried logs to create mushroom habitats. Inside the beds, vegetables, flowers, and shrubs offer the requisite shade and humidity for mushroom cultivation. In weedy areas, Litchfield suggests putting down organic material and covering it with wet cardboard and wood chips, an ideal substrate for fungi.(Litchfield, 2002)

These methods of production are not likely to yield huge numbers of mushrooms. However, they can provide an attractive addition to directly marketed produce.

Mushrooms in Permaculture* Design

*Permaculture is a system of combining perennials, trees, shrubs, and vines to create a "permanent agriculture." Using an intensive design process, the natural elements of an ecosystem are replaced by food-producing relatives, creating an edible landscape.

Paul Stamets was an early advocate of integrating a variety of mushrooms into a permaculture system.(Stamets, 1994) In his design, agricultural wastes like cornstalks, wheat straw, or rice straw can be used as growing media for oyster mushrooms. After harvest, the spent substrate can be recycled as fodder or mulch for garden soils.

Shaggy manes (Coprinus comatus), Stamets notes, do well on manured soils and near compost piles. The King stropharia or wine cap mushroom (Stropharia rugoso-annulata) grows best outdoors and plays a key role as a recycler of woody debris. Bees, attracted to the sweet mycelium, help pollinate the green garden plants. The mushrooms are good to eat when small. Large, mature mushrooms attract fly larvae that make excellent fish or poultry food. These can supplement feed for other on-farm enterprises or be sold to pet stores.

Stamets also uses King stropharia mushrooms for their ecological benefits. He found that, when established along waterways, they acted as microfilters of fecal coliform bacteria generated by his small herd of cattle. He also planted them along greywater runoff areas. Stamets believes mushrooms can play a large role in mycofiltration.(Stamets, 2000-2001)

Stamets grows shiitakes, namekos (Pholiota nameko), and Lion’s mane (Hericium erinaceus) mushrooms on inoculated logs set in a fence row, while other species like maitake (Grifola frondosa), reishi (Ganoderma lucidum), and clustered wood-lovers are cultivated on stumps as part of a hardwood forest management system. He introduces mycorrhizal species such as chanterelles, King boletes, and others to new areas by "satellite planting," in which seedlings are planted near trees that have a desired mushroom species growing around them. After several years, the seedlings and their mycorhizal associates are transplanted, creating new patches of mushrooms. Morels are more difficult to propagate, but some types can be encouraged through the use of small burns.

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Choosing a Mushroom Species

A mushroom cultivation kit (check with suppliers listed below) is a handy way to begin to understand the fungal life cycle. Once you successfully use the kit, you can begin to learn the steps that precede that final fruiting stage of the mushroom life cycle. Purchase spawn that will grow on materials you have available. Then design and test a system that duplicates the conditions favorable to all stages of growth. You can use this experience to learn how to create sterile cultures and spawn for the species you are growing.

Choose the species to grow by thinking about:

  • What waste materials are readily available to use as a growth medium?
  • What kind of facility or environment is available?
  • How much will the necessary equipment cost?
  • What level of skill is required to manage the life cycle of the fungus?
  • What is market demand for this species?

According to these criteria, oyster (Pleurotus species) and shiitake (Lentinus edodes) mushrooms are probably best for most novices, although the maitake (Grifola frondosa) is also a possibility. The former two are relatively easy to grow, and there is already a market for them, largely because commercial producers of white button (Agaricus bisporus) mushrooms have been diversifying into specialty mushrooms. If you intend to grow mushrooms commercially, shiitake or oyster mushrooms are your best choices. These two species are more thoroughly covered in the following sections.

A chart in the Appendix lists other common species and the materials on which they can be cultivated. Test each species you are considering against each of the questions listed above.

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Species for Beginners

Oyster mushrooms

Flamingo Oyster Mushrooms
Flamingo Oyster Mushrooms
Glen Babcock
Garden City Fungi

Oyster mushrooms (Pleurotus species) are a good choice for beginning mushroom cultivators because they are easier to grow than many of the other species, and they can be grown on a small scale with a moderate initial investment. Although commonly grown on sterile straw from wheat or rice, they will also grow on a wide variety of high-cellulose waste materials. Some of these materials do not require sterilization, only pasteurization, which is less expensive. Another advantage of growing oyster mushrooms is that a high percentage of the substrate converts to fruiting bodies, increasing the potential profitability.

Oyster mushrooms can become an integral part of a sustainable agriculture system. Many types of organic wastes from crop production or the food processing industry can be used to support oyster mushroom production.

Although there are no books devoted entirely to oyster mushroom production, Stamets' books provide basic information. Research on using various agricultural and forest wastes as substrates is reported in the recently published Mushroom Biology and Mushroom Products, edited by D.J. Royse.(Royse, 1996) Peter Oei (Oei, 1991) documents a number of commercial production systems for some strains grown in developing countries.

There are an increasing number of Web sites devoted to oyster mushroom production. Lawrence Weingarten describes his production process on his Web site, complete with photos at

A Canadian Web site also offers additional advice:
Oyster Mushroom Cultivation (Site http://www.gov.ns.ca/nsaf/elibrary/archive/hort/vegetables/pihve94-03.htm no longer active.)

The MushWorld Web site, contains excellent technical information about growing oyster mushrooms. The site requires registration, but it is free.

Golden Oyster Mushrooms
Golden Oyster Mushrooms
Glen Babcock
Garden City Fungi

Oyster mushroom cultivation has one significant drawback: some people are allergic to the spores. In these cases, air-cleaning equipment or respirators are necessary in order to safely work in the production facility.

The consumer market for oyster mushrooms is being developed by the larger mushroom companies as they diversify their operations. However, because of the short shelf life of many oyster mushroom varieties, this species may offer a special advantage to the local grower who markets directly and can consistently deliver a fresh, high-quality product.

Shiitake mushrooms

Shiitakes (Lentinus edodes) are well suited as a low-input alternative enterprise because they, like oyster mushrooms, can be grown on a small scale with a moderate initial investment. Shiitake cultivation has been thoroughly investigated, and a commercial market already exists in most areas of the United States. Shiitake mushrooms are grown on logs, either inside or outside. Inside, they can also be grown on compressed sawdust logs or in bottles or bags. See the brief description of these production systems below. Several excellent books and Web sites are also listed below in Resources (shiitake).

Log Production

Hardwood logs approximately 4" to 6" in diameter and of an easily handled length (commonly four feet) are cut during a tree's dormant season. Oaks, sweetgum, cottonwood, beech, birch, willow, and other non-aromatic hardwoods are appropriate species. The denser woods produce for up to twice as long as the softer ones. Smaller diameter logs produce more quickly than larger ones, but for a shorter time.

Handle the logs carefully to avoid soil contact and damage to the bark. This will help prevent contamination by competing fungi. Inoculate the logs with spawn from a strain suitable to your production system. There is a wide variety of spawn from which to choose and several inoculation methods.

After inoculation, the spawn develops a thread-like network—the mycelium—growing throughout the log. During this time, you must protect the logs from dehydration by the sun and wind. Spray or mist the logs to maintain the humidity necessary to keep the mycelium alive and growing. When the mycelium has fully occupied the logs and the temperature and humidity are right for fruiting, the mycelium will initiate tiny "pinheads" at the surface of the log. The pinheads grow into mushrooms in the next couple of days.

To stimulate fruiting, some growers soak the logs in water tanks and/or "shock" them by physical impact or chilling. Others leave the logs in the growing environment and harvest when they naturally fruit.

Be alert for signs that fruiting is beginning. The best grades of shiitakes have caps that still have a slight curl at the edge. Harvest often if you want to earn the best price for your mushrooms. In addition, if you want to deliver a premium product, you must pay attention to post-harvest storage, packaging, and shipping.

Many shiitakes are raised organically. Although it is easier to produce shiitakes organically than some of the other mushrooms, "weed" fungi, as well as pests such as slugs and flies, can reduce fruiting and quality. The producer must monitor, quickly identify, and control these pests or lose some of the crop.

Federal law now controls the use of the word "organic" in marketing. In order to label a product organic, producers must be certified by an accredited third party and document their production and handling practices. For further information, see the ATTRA publication Organic Farm Certification & the National Organic Program.

Growing Shiitakes on Sawdust

Today, most shiitakes and many other mushroom species are raised on a sterilized sawdust substrate. Although this method allows a much faster fruiting cycle and a high level of return (110% or more of initial dry weight), it also demands a greater capital investment and more skillful management than log production. In order to achieve fruiting as quickly as possible, you need a building in which you can control the temperature and moisture. The building must be easy to keep clean, and sanitary procedures must be strictly followed to avoid contamination.

The chamber and the steam processor to pasteurize or sterilize the sawdust can represent a significant initial investment. For example, Crop King sells a small mushroom production system, including an inoculation table and bagging station, for about $5,000. The company's complete growing system—including equipment, structural components, and technical support—can come to more than $41,000. Recovering these costs is a challenge for a beginner—especially at current mushroom prices.

Shiitake mushrooms fruiting on sawdust
Shiitake mushrooms
fruiting on sawdust.

Glen Babcock
Garden City Fungi

However, innovative producers have used concrete mixers to blend supplemental ingredients and made pasteurized substrate in barrels. Fungi Perfecti sells pressure sterilizers for $200 to $1,000, but warns that they are not designed for commercial production.

Using hydrogen peroxide instead of conventional pasteurization is a relatively recent innovation. A manual on this method and more information is available at http://www.mycomasters.com/.

Growing mushrooms on sawdust requires attention to detail—especially careful monitoring and timely processing of the blocks, bottles, or bags. Several of the books listed below, including Stamets (1993) and Przybylowicz and Donoghue (1990), offer more details about this production method.

Shiitake Prices

The price for shiitake mushrooms fluctuates throughout the season. Prices are highest in the winter when supply is low, and lowest in summer when production peaks. Except in very mild climates, the only logs that fruit in winter are those maintained indoors. Using strains selected to fruit at cooler temperatures can lengthen the harvest season and allow producers to capture the higher prices. See the marketing section below for ways to counteract the natural price cycle.

Sources of Further Information on Shiitakes

Several states, including Pennsylvania, California, and Oregon, support university research on shiitakes and may have Extension specialists who can provide information to growers in their states. Others have Extension publications with information specific to their areas. Some of these resources are available on-line at Web sites listed in the Resources section. An excellent example is the site maintained by the Ohio State University.

In states without this Extension support, one of the best ways to learn about production is to share information with other growers. There are several local grower organizations, many of which publish newsletters. Ask your state Extension horticultural specialist about local organizations, or you can contact the North American Mycological Association or the American Mushroom Institute (see Resources). There are also several books specifically about shiitake production. See Resources: (shiitake) for more information.

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Other Mushroom Species

Mushroom Species with Limited Commercial Production

Some species of mushrooms are not yet commercially cultivated. Many of these are mycorrhizal types; that is, they grow only in conjunction with the roots of a higher plant. Matsutakes and chanterelles are typical examples of such mushrooms.

Mycorrhizal mushrooms are the hardest to grow commercially, because the needs of both the fungus and the host plant must be met in order to produce a commercial crop. Also, the host plant typically must reach a certain physiological maturity before the fungus will fruit. When the host is a tree, this maturation may be measured in decades. Nevertheless, highly prized morels and truffles are mycorrhizal, and they are both now being grown commercially in the United States.


Commercial production of morels on anything but a small-scale, seasonal basis is currently not a practical option. Morels are being grown year-round, using a patented process, at only one production facility in North America (in Alabama). The patent and facility are owned by Terry Farms and represent the only successful commercial process for fruiting these highly valued mushrooms out of season.

It is, however, possible to establish a morel patch by using a morel starter kit. If you are successful, these mushrooms will fruit in the spring at the same time as wild morels. Morel prices are, understandably, at their lowest during this natural fruiting season. Adding them to a farmers’ market stand would certainly attract morel-loving customers. You can also dry the product for year-round sales if you can grow commercial quantities in your patch.

Tom Volk’s Web site, has particularly good information about morel mushroom production.


Growers generally begin truffle production by dipping tree seedlings in a mycorrhizal slurry before planting. After several years, under favorable growing conditions for both the tree and the fungus, truffles form underground fruiting bodies that roughly resemble potatoes. These range from the size of a pea to that of a fist and give off a distinctive odor. Since these "mushrooms" don't completely emerge from the ground, they have traditionally been sniffed out by pigs or trained dogs.

The requirements for growing the black Perigord truffle, Tuber melanosporumGarland, 1996) Garland also has a consulting business and sells inoculated trees. Vitt., include choosing an appropriate host plant (usually oak or hazelnut), inoculating its roots with the spawn, and planting it. Frank Garland planted his first inoculated trees in 1980 and harvested the first black truffles grown in the U.S. on October 23, 1993. He has written a production guide based on his experience.(

One Oregon tree farmer in prime white truffle country found a low-fuss method of cultivation. The white truffle, Tuber gibbosum, is a mycorrhizal species associated with Douglas fir and other conifers. This farmer uses a backpack sprayer to apply a slurry made of truffles and spores at the roots of conifers. The inoculated areas have produced between 300 to 1000 pounds per acre per year, significantly more than the unsprayed areas.(Arnold, 1996)

The truffle industry has developed rapidly in Australia and New Zealand. New Zealand's efforts, as reported by Dr. Ian Hall, were begun in 1987, with harvest recorded on June 29, 1993, just months before Garland found his first truffles in North Carolina. Australian researchers also report success in their cultivation efforts, summarized in several articles available on the Web. The articles are found by searching the following main pages for "truffle" or "Tuber melanosporum":

The Black Truffle (Hall et al., 1994) is out of print, but it was converted to CD ROM format in 2001 and is available for NZ$49.95 through the Internet at:
https://secure.crop.cri.nz/cart/catalog/product_info.php?products_id=30. Chapters cover the symbiotic partnership between truffles and their host plants, history and folklore, cooking and recipes, how to establish and manage a plantation, climatic and soil requirements, and cultivation and harvesting.

Studies have revealed a lot about the conditions necessary to bring truffles to early fruiting and then to significant production levels. However, because of the crop's extremely high value and because each success has required an investment of considerable time, it is understandable that some of this information is considered proprietary. Even when fruiting begins, growers themselves may not be able to accurately identify what contributed most to the truffles' growth. Each new truffle enterprise is an experiment based on what has already been reported.

Consider combining the production of truffles with the sale of nuts from the host trees, growing annual or perennial crops between the trees, or grazing ruminants among them—sheep have been credited with increasing the French wild-harvested crop yield.(Ludmer-Gliebe, 1997) These or other agroforestry options could provide additional sources of income during early, non-fruiting years and in the seasons when truffles do not produce.

Other Mycorrhizal Species

Mushroom researchers continue to investigate the cultivation of other species for the commercial market. A loosely organized group of international scientists meets intermittently to share their research. The Web site maintained for this scientific endeavor is located here:

Until commercial production systems are developed, mushrooms such as chanterelles and matsutake (pine) mushrooms will continue to be collected from the wild for sale to the specialty mushroom market. The harvest of wild mushrooms is strictly regulated in some states. Check with your state department of agriculture regarding laws that apply. You would be wise to carry liability insurance and to be absolutely certain of the identity of mushrooms you sell. Mistakes can be fatal to the consumer. Finally, the forest environment that supports the growth of wild mushrooms is a fragile one. Learn how to conduct your foraging business in a way that protects future harvests.

Mushroom the Journal (see Resources) provides excellent information on wild mushrooms. There are also many local mycological societies that schedule "forays"—trips to known mushroom habitats—where the inexperienced forager can learn about various species and how to identify them.

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Pest Management

Integrated pest management (IPM) is a least-toxic approach for managing any pest. IPM views pests as a natural part of the farm environment. The integrated management of a pest is accomplished by altering the environment to the disadvantage of that pest. In order to accomplish this, you have to be able to identify what pests are active, how many there are, and how many it takes to hurt your profits. If you know the life cycle of each problem organism, you can take measures to make it hard or impossible for it to complete its life cycle. You may be able to encourage natural enemies that will keep the population below the economically damaging threshold.

Here are some examples of non-chemical methods used to control typical pests in the production of white button mushrooms. Mushroom flies, a common pest among many cultivated mushrooms, are attracted to the smell of decaying vegetation such as mushroom substrates. Screening the mushroom house ventilation system will keep adult flies out. Double doors and positive atmospheric pressure within the structure also prevent flies from entering. Since adult fungus flies are drawn to standing pools of water on benches, walks, or floors, places where water can collect should be eliminated. Biocontrol is another option for several mushroom pests, the sciarid fly among them. A predatory nematode attacks this fly in its larval form. Therefore, this nematode can be added to the composting substrate to prevent infestation.

For a better understanding of IPM, see the ATTRA publication Biointensive Integrated Pest Management. It describes IPM methodology and provides extensive resources for further research.

Each mushroom species in a specific environment has a different pest complex. Because specialty mushroom production in this country is still very new, many pests have not received research attention. Most pests you are likely to encounter, however, have probably already been studied. In any case, you will probably have to design your own pest management system. Stay alert for any evidence of damage to the fruiting mushrooms and act quickly to identify its cause. Use whatever information you can find, along with your own creativity, to devise ways to protect your crop.

Use all the resources you can find—in libraries, at bookstores, or on the Web. Local Extension agents or state Extension specialists can help identify pests and, possibly, determine economic thresholds. They can also help you find biological controls, if cultural and mechanical methods fail.

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Marketing Mushrooms

Marketing is the most important consideration of all. If you can't sell your mushrooms at a price that ensures a reasonable profit margin, you don't want to invest in this enterprise. Spend some time—and even some money—educating yourself about marketing your potential product.

This section provides a broad overview of market trends, some ideas about how to research potential markets, references to useful resources, suggestions about marketing channels, and advice on financial analysis.

Market research and evaluation is perhaps the most challenging part of developing a new enterprise. Luckily, there are many helpful sources. A good place to start is ATTRA's Marketing and Business series, particularly Direct Marketing and Evaluating a Rural Enterprise . These publications detail the market evaluation process and include extensive resource lists. Other relevant ATTRA publications cover market gardening, value-added products, and agri-tourism. You can find the marketing publications on the ATTRA Web site by visiting Marketing, Business & Risk Management, or call 800-346-9140 to have them sent to you.

The many Web sites listed in Resources (below) will help you find information to further your market research. Another resource, as you analyze the potential for a mushroom business, is your local Small Business Administration office. Not only do they have helpful publications, they also provide some one-on-one assistance.

The Mushroom Business

Stella K. Naegely writes in the American Vegetable GrowerNaegely, 2000) that the key to the mushroom business is to have established buyers and be capable of consistent production. New growers might encounter an uphill educational experience for two or three years. Launching a commercial mushroom operation can cost between $50,000 and $250,000, depending on whether a grower starts with an appropriate building. For that reason, it is prudent to start small. Naegely offered the following business tips for people contemplating commercial production.(

  • Make the market drive your production. Talk to potential buyers about volume and prices.
  • Explore various marketing options: brokers, distributors, farmers’ markets, restaurants, grocery stores, food service operations, and co-ops.
  • Consider reselling other growers’ mushrooms to offer more variety and larger volume.
  • Talk to other producers and perhaps a consultant about production systems.
  • Consider buying used equipment to reduce initial capital investment.
  • Strike a balance between undercapitalizing and a heavy debt load.

Market Demand

Some 260 U.S. growers produced more than 844 million pounds of mushrooms in 2002-03, with a farm gate value of $889 million. (Certified organic mushrooms accounted for only 1 percent of all sales, although 12 percent of growers were certified organic.). The vast bulk of sales were of the Agaricus species, which includes white button mushrooms, portobellas, and criminis. The latter two are a brown strain of Agaricus bisporus, whose cultivation is managed for extra large (portobella) and very small (crimini) fruiting bodies. (Current statistics are found at http://usda.mannlib.cornell.edu/reports/nassr/other/zmu-bb/.)

Large, well-established companies produce virtually all Agaricus mushrooms; most are located in Pennsylvania and California. Their production houses are full of mushrooms in every stage of development. Mushrooms raised in these systems can be sold profitably on the wholesale market. It is very difficult for a beginning grower to compete with these companies at wholesale prices.

Market Research

The goals of market assessment are to project the sales volume and gross income of a new enterprise, to analyze its potential profitability and cash flow, and to gather information about potential buyers and competitors (to help develop a market strategy).

Many specialty mushrooms can be cultivated, but the market, though growing, is still limited. If you are thinking about starting a commercial mushroom enterprise, begin at the end: to whom will you sell them? You cannot make money in any business if you don't have buyers for your product. Learn who buys mushrooms, what kinds they want, and where they shop. You must thoroughly investigate the demand for each mushroom species or product— as well as the available marketing outlets— before committing large amounts of capital to the enterprise.

Check the local situation on your own.Some common methods for conducting initial research include observation of buyers, surveys of stores, personal interviews with growers, and test marketing (once you have an experimental product). Another function of market research is to evaluate the competition. This will help you determine what market already exists and identify any niches you could fill. To find out more about your competitors, use their products. Talk to them. You may be surprised how much information they will share.

Market Channels

Explore as many marketing strategies as appeal to you. Below are some possibilities.

  • Market the fresh or dried product directly to your customers (at farmers' markets, to gourmet chefs, over the Internet, through mail-order offerings)
  • Add value to the mushroom by creating processed products (mushroom sauces, dried entrée mixes, teas, extracts)
  • Wholesale as fresh produce (on contract or by the batch)
Direct marketing

If you can sell your mushrooms or mushroom products directly to an end user, you will naturally receive a better price than if you sell to a wholesaler. Direct marketing of mushrooms at local farmers' markets, to restaurants, or in supermarkets is possible in many locations. When competing in local markets, excellent service, top quality, and consistent supply, rather than the lowest price, might win the sale, particularly with gourmet chefs. Some chefs specialize in locally grown foods and may be interested for that reason. Others are willing to pay for fresh, premium produce. In any case, establishing a relationship with the buyer and reliably delivering a quality product are essential for this type of marketing.

Local grocery stores are another potential buyer of fresh mushrooms. However, an Arkansas grower found that local grocery chains were interested in her shiitake mushrooms only if she could assure them of a year-round supply. She decided that she had to add indoor production in order to meet this requirement. Natural foods stores are a market that may be more tolerant of seasonal supply. Any chef or grocer will require assurances of both quality and regular supply before switching from established wholesale sources.

Although the wholesaler with an established account creates stiff competition, the small, efficient producer might still have an advantage in some niche markets. For instance, shiitakes grown on logs are generally of higher quality and have a longer shelf life than shiitakes grown on sawdust substrates (the most common mass-production method). Log-grown shiitakes earn prices from three to eight times higher than those grown on sawdust substrates.(Anon., 2003) Find the buyer to whom quality matters, and you will have found a market for your product.

Locally-grown oyster mushrooms have an advantage because oysters have a very limited shelf life and are too fragile to ship easily. The grower with direct, local sales can supply a fresher product that arrives in better condition.

Wholesale markets

Selling fresh mushrooms to a wholesaler will mean a lower price than if you market directly. However, for growers who choose not to involve themselves in direct sales, there are established wholesale markets for mushrooms. Wholesalers advertise in produce industry periodicals like The Packer. Your local librarian or an Internet search can help you locate other such magazines.

Mr. Paul Goland of Hardscrabble Enterprises maintains that there is a steady and growing market for quality dried shiitakes, even though the wholesale market has been depressed by Chinese imports. His buyers—natural foods stores and co-ops—do not buy the Chinese products. He buys several grades of dried shiitakes from growers who ship directly to West Virginia. Contact Paul Goland (see References) to learn whether he has a current demand for your product.

Small-scale commercial production of white button mushrooms and other Agaricus varieties such as portobellas and criminis is not recommended for the beginner, except on a small scale for direct marketing. A significant capital outlay and a high level of management skills are required to begin production, and at current prices, recovery of the initial investment might not be possible. The market is extremely competitive. More information about the button mushroom business is available from The American Mushroom Institute (see Resources).

Adding Value to Fresh Mushrooms

Adding value to fresh mushrooms usually means either developing a processed product, such as a sauce, or drying surplus mushrooms for sale in the off-season, when prices are higher. A value-added product can be sold either directly to the consumer or to wholesalers.

The Persimmon Hill Berry Farm in Missouri (see References) offers an example of how a small entrepreneur can create and market a value-added mushroom product. Persimmon Hill developed a recipe for a shiitake mushroom sauce and invested in a commercial kitchen to produce it. The farm buys from local growers who, since the mushrooms are not for the fresh market, can freeze them until they have enough to make a delivery to the processing kitchen worthwhile. During warm weather, when production peaks, they can likewise freeze the shiitakes until Persimmon Hill needs them. These growers receive a better price than they would if they were selling at the lower, peak-season prices, and Persimmon Hill is ensured a steady supply for its sauce. Persimmon Hill sells its products on the Internet and through direct sales on the farm.

Drying shiitakes and other mushrooms is another way to add value and avoid the low prices of the peak season. For more on drying technologies, see the ATTRA publication Options for Food Dehydration. (After drying, mushrooms should be held at 0° F. for four days to kill any surviving pest eggs.)

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Financial Analysis

As a part of your market research, you need to do a financial analysis of the potential enterprise. Develop an enterprise budget with as much detail as you can provide. As with many farm enterprises, mushroom production is often only marginally profitable when labor and management costs are taken into consideration. An example of an enterprise budget for shiitake log production is available at:
www.ext.vt.edu/pubs/vegetables/438-898/shiitakemushrooms.pdf. (PDF / 6 kb) Download Acrobat Reader

Using this format or a generic enterprise budget from Extension offices or off the Internet, fill it in with as many actual calculations and estimates of costs as you can. If you are considering several mushroom species, do a financial analysis of each one separately. Try to anticipate every cost so that you can construct an accurate financial picture. Include an educational and/or marketing component in your budget, allowing for free samples or flyers with information and recipes, especially if you are developing a new product or will be doing direct marketing.

If you are adding mushroom production to an integrated farming system, financial analysis is more difficult. Making a clear profit might not be as important as making use of off-season labor or the small logs from woodlot thinning to create a saleable product from what otherwise would have been waste.

Only by developing a market niche for a high-quality fresh product or by producing a mushroom-based food item can a small-scale beginner hope to compete.

Case Study: Marketing Key for Small-Scale Growers

In the Ozarks of Missouri, Nicola MacPherson and her husband, Daniel Hellmuth, have grown shiitakes on three acres for nine years. The couple grow them the traditional way on oak logs, and they market them under the label Ozark Forest Mushrooms, which carries a USDA organic seal. To sell their mushrooms, however, they've relied on a variety of nontraditional marketing approaches. "To promote sales, you must be prepared to promote your product tirelessly," MacPherson says. Their principal markets are up-scale restaurants, catering companies, and gift catalogs. Customers who demand organic produce, such as CSA (Community Supported Agriculture) subscribers, also provide a reliable market.

MacPherson urges beginners to start modestly, learn the process thoroughly, and develop a small, reliable customer base—say, a half-dozen regular customers—as a foundation. (She offered free samples to help establish a local market.) She cautions new growers not to create a market demand that they cannot meet. Selling to supermarkets, for instance, can be fraught with problems, including the challenge of ensuring product freshness and the recurring need for educating new produce department employees.(Anon., 1998)

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Further Resources

Two periodicals that include mushroom cultivation information are The Mushroom Growers’ Newsletter and, to a lesser degree, Mushroom the Journal. Subscription information is included, along with citations for several key books, in the Resources section below. Web sites devoted to mushrooms and their cultivation are increasing every year. A selected list of mushroom Web sites is included below.

Some state or local mycological societies have groups interested in mushroom cultivation. To locate chapters in your area, contact the North American Mycological Association (see Resources).

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Commercial cultivation of mushrooms is not for everyone. It requires someone who is familiar with fungi life cycles and willing to commit time and money to research, designing a system, and developing a business. The mushroom cultivator must be able to carry out operations on time, be attentive to details, and be vigilant about pest invasions. In most cases, marketing requires excellent public relations skills.

Nevertheless, there is potential for an innovator who can use an existing facility, obtain a low-cost substrate, and produce a reliable supply of a high quality product. As part of a whole-farm system, mushrooms can augment productivity at any scale. Producing a nutritious food at a profit, while using materials that would otherwise be considered "waste," constitutes a valuable service in the self-sustaining community we might envision for the future. It is a challenge some will find worth taking.

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Anon. 1998. Grower’s business is ‘mushrooming.’ Small Farm Digest. Winter. p. 3.

Anon. 2003. Small Farms Research News. Spring. p. 3.

Arnold, Ralph. 1996. Grow fungi without the sterile trappings? Mushroom the Journal. Summer. p. 35.

Beauséjour, Terri Marie. 1999. Mushrooms in the garden. Mushroom the Journal. Fall. p. 17–19.

Cooner, Deanna. 2001. Mushroom farming. AgVentures. June-July p. 14–15.

Edwards, Richard. 2000. The missing link? Mushrooms in permaculture. Permaculture Magazine. No. 25. p. 37–39.

Garland, Franklin. 1996. Truffle Cultivation in North America. Garland Gourmet Mushrooms and Truffles, Inc., Hillsborough, NC. 41 p.

Available for $15 from:

Garland Gourmet Mushrooms and Truffles, Inc.
3020 Ode Turner Rd.
Hillsborough, NC 27278
919-732-6037 FAX
E-mail: truffleman@mindspring.com

Green, Judy. 1988. Doing your own market research. Farming Alternatives. Cornell University Resource Sheet #6. November. 6 p.

Hall, Ian R., G. Brown, and J. Byars. 1994. The Black Truffle. Rural Industries Research and Development Corporation. New Zealand. 107 p.

Hardscrabble Enterprises, Inc.
P.O. Box 1124
Franklin, WV 26807
E-mail: hardscrabble@mountain.net
Contact: Paul Goland

Park, Kwnag-ho. 2001. Nutritional Value of a Variety of Mushrooms. January. 5 p.

Litchfield, Ken. 2002. In your yard: More than grass, shrubs and trees. Mushroom the Journal. Summer. p. 20–23.

Ludmer-Gliebe, Susan. 1997. Sheep are essential to French truffle production. November. p. 4–5.

Naegely, Stella K. 2000. Is there money in mushrooms? American Vegetable Grower. February. p. 40–43.

Oei, Peter. 1991. Manual on Mushroom Cultivation. TOOL Foundation, Amsterdam. p. 49–50. (A new edition of this book is now available; see Resources.)

Persimmon Hill Berry Farm
RR 1 Box 220
Lampe, MO 65681

Royse, D.J. (ed.). 1996. Mushroom Biology and Mushroom Products: Proceedings of the Second International Conference, University Park, PA, June 9-12, 1996. Penn State, State Park, PA. 581 p.

Royse, Daniel J., and Lee C. Schisler. 1980. Interdisciplinary Science Reviews. Vol. 5, No. 4. p. 324–331.

Stamets, Paul. 2000–2001. A novel approach to farm waste management. Mushroom the Journal. Winter. p. 22. Or see at www.fungi.com/mycotech/farmwaste.html.

Stamets, Paul. 1994. Permaculture with a mycological twist. The Permaculture Activist. May. p. 8–10.

Stamets, Paul, and Jeff Chilton. 1983. The Mushroom Cultivator. Agarikon Press, Oympia, WA. 415 p.

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Mushroom Cultivation Media
Growing Medium
Mushroom Species

Rice straw

Straw (Volvariella)

Oyster (Pleurotus)

Common (Agaricus)

Wheat straw

Oyster (Pleurotus)

Common (Agaricus)


Straw (Volvariella)

Coffee pulp

Oyster (Pleurotus)

Shiitake (Lentinus)


Shiitake (Lentinus)

Oyster (Pleurotus)

Lion's Head or Pom Pom (Hericium)

Ear (Auricularis)

Ganoderma (Reishi)

Maitake (Grifola frondosa)

Winter (Flammulina)


Oyster (Pleurotus)


Cotton waste from textile industry

Oyster (Pleurotus)

Straw (Volvariella)

Cotton seed hulls

Oyster (Pleurotus)

Shiitake (Lentinus)


Nameko (Pholiota)

Shiitake (Lentinus)

White jelly (Tremella)

Sawdust-rice bran

Nameko (Pholiota)

Ear (Auricularis)

Shaggy Mane (Coprinus)

Winter (Flammulina)

Shiitake (Lentinus)


Oyster (Pleurotus)

Lion's Head or Pom Pom (Hericium)

Shiitake (Lentinus)


Oyster (Pleurotus)


Horse manure (fresh or composted)

Common (Agaricus)

Crushed bagasse and molasses wastes from sugar industry

Oyster (Pleurotus)

Water hyacinth/Water lily

Oyster (Pleurotus)

Straw (Volvariella)

Oil palm pericarp waste

Straw (Volvariella)

Bean straw

Oyster (Pleurotus)

Cotton straw

Oyster (Pleurotus)

Cocoa shell waste

Oyster (Pleurotus)


Oyster (Pleurotus)

Banana leaves

Straw (Volvariella)

Distillers grain waste

Lion's Head or Pom Pom (Hericium)

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The Mushroom Growers' Newsletter is a monthly newsletter that contains cultivation information and current prices of mushrooms at San Francisco and New York markets.

Available for $35/year from:

The Mushroom Growers' Newsletter
P.O. Box 5065
Klamath Falls, OR 97601

Mushroom the Journal is a quarterly publication that primarily contains information on foraging, with limited information on cultivation.

Available for $19/year from:

Leon Shernoff
1511 E. 54th St.
Chicago, IL 60615


The National Agricultural Library (NAL) has published several Quick Bibliographies (QBs), results of database searches on a given topic. QBs have been published for both shiitake and oyster mushrooms. They can be downloaded from the NAL Web site located at:


Stamets, Paul, and J.S. Chilton. 1983. The Mushroom Cultivator. Agarikon Press, Olympia, WA. 415 p.

Includes growing parameters for 16 species and covers every aspect of mushroom cultivation.

Available for $29.95 from:

Fungi Perfecti
P.O. Box 7634
Olympia, WA 98507
800-780-9126 (toll-free) or 260-426-9292

Stamets, Paul. 1993. Growing Gourmet and Medicinal Mushrooms. Ten Speed Press. Berkeley, CA. 592 p.

Companion volume to The Mushroom Cultivator. This third edition updates cultural and growing techniques, adds growing information on new varieties, and discusses strain selection for cultivation.

Available for $44.95 from Fungi Perfecti (See address above.)

Oei, Peter. 2003. Manual on Mushroom Cultivation: Techniques, Species and Opportunities for Commercial Application in Developing Countries. TOOL Publications, Amsterdam, The Netherlands. 274 p.

First published in 1991, and now completely updated, this guide offers information on growing 12 species of mushrooms, with a particular emphasis on growing in developing countries. The manual includes 71 drawings, 93 photo illustrations.

Available for $53.50 plus $8 for shipping from:

Western Biologicals, Ltd.
P.O. Box 283
Aldergrove, BC V4W 2T8
604-856-3339 (telephone or FAX)

Also available to developing countries from C-Point Publishers in the Netherlands. For ordering information, contact Ine Klerkx , ine.klerkx@cpoint.nl.

Hadeler, Hajo. 1995. Medicinal Mushrooms You Can Grow. The Cariaga Publishing House. 196 p.

Excellent guide to wood-loving mushroom cultivation, from plugging old stumps to enriched sawdust culture in sterile bags. Covers medicinal species well. Well written and illustrated; index.

Out of print, but some are still available from amazon.com

Hobbs, Christopher, and Michael Miovic (ed.). 1995. Medicinal Mushrooms: An Exploration of Tradition, Healing and Culture. Third Edition. Botanical Press, Santa Cruz, CA. 252 p.

Mushroom toxicity, use in traditional medicine and in the human diet are supported by clinical studies and explorations of cultural influences in this technical coverage. More than 100 species of edible fungi are documented.

Widely available for $18.95.


The North American Mycological Association (NAMA) publishes a bi-monthly newsletter, The Mycophile, and publishes an annual directory that provides names and address of all NAMA members and every mycology association in North America. FNAMA focuses more on finding and identifying wild mushrooms than commercial cultivation.

Annual membership is $35. Contact:

336 Lenox Ave.
Oakland, CA 94610-4675

The American Mushroom Institute is a source of information on the mushroom industry. It serves mainly large, highly capitalized commercial producers.

AMI Washington DC Office
One Massachusetts Avenue, N.W.
Suite 800
Washington, D.C. 20001

AMI Avondale Office
1284 Gap Newport Pike
Suite 2
Avondale, PA 19311

Web sites

[Note that addresses may change. A search of the Web should provide current locations.]

How to Grow Mushrooms
www.gov.ns.ca/nsaf/elibrary/archive/hort/organic/990015.htm (Site no longer active.)

From the Nova Scotia Department of Agriculture and Fisheries, this Web page offers a good overview of growing mushrooms in compost.

Six Steps to Mushroom Farming

From the Pennsylvania State University Agriculture Extension Service, this page describes step by step phase I composting, phase II composting, spawning, casing, pinning, and cropping.

Permaculture with a Mycological Twist: The Stametsian Model for a Synergistic Mycosphere

This article carried on the Fungi Perfecti Web site describes permaculture applications for mushrooms. (See the sidebar.)


"Total mushroom information" is the banner claim here. This excellent resource features sections on cultivation, pests and disease, and medicinal mushrooms, as well as the monthly webzine Mushworld. Requires free registration for access. Highly recommended.

Penn State Mushroom Spawn Laboratory

A comprehensive Web site with resources on mushroom science and cultivation.

Gourmet Mushrooms

Source of mushroom kits and mushroom nutraceuticals; extensive bibliography on the medicinal value of mushrooms

Fungal Jungal: Western Montana Mycological Society

A good example of a regional mycological society Web site filled with diverse resources, including information on morels, fire ecology, a western mushroom photo guide, and recipe lists.

The Mushroom Council

Home of the mushroom industry's marketing council, this site contains useful information about consumer buying trends and providing for food service needs as well as nutritional and production information; focuses mainly on Agaricus spp. with no specialty mushroom differentiation.

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Resources (shiitake)

Bibliography: shiitake

Rafats, Jerry. 1996. Shiitake: Cultivated Mushroom. Quick Bibliography Series B:90-4. National Agricultural Library, Beltsville, MD.

A bibliography of articles on shiitake mushrooms. Though somewhat dated (published in 1996), this collection still contains valuable information for shiitake producers. It's available on-line at:

Books: shiitake

Harris, Bob. 1994. Growing Shiitake Commercially. 2nd Ed. Science Tech Publishers, Madison, WI. 72 p.

Large-scale cultivation of shiitake mushrooms using traditional oak logs. Based on many years' work, including material from recent visits to Japan. Some of the most modern and cost-effective methods are presented with photographs and drawings.

Available from Mushroompeople (See Suppliers).

Kozak, M.E., and J. Krawcyzk. 1993. Growing Shiitake Mushrooms in a Continental Climate. 2nd Ed. Field & Forest Products, Peshtigo, WI. 114 p.

Describes step-by-step year-round shiitake cultivation, from log inoculation to fruiting. Excellent reference for inland producers

Available for $17.50 postage paid from Field & Forest Products, Inc.
(See Suppliers.)

Przybylowicz, Paul, and John Donoghue. 1990. Shiitake Growers Handbook. Kendall/Hunt Publishing Co., Dubuque, IA. 217 p.

Book covers a wide range of topics, from log cultivation to sawdust cultivation. Information includes both scientific material and practical advice. Emphasis is on presenting as much information as possible rather than selectively choosing the best or most advanced methods.

Widely available for $25.

Jones, Kenneth. 1995. Shiitake: The Healing Mushroom. Healing Arts Press, Rochester, VT. 128 p. www.parkstpress.com/titles/shiita.htm

This book describes the nutritional benefits and traditional uses in Chinese medicine for shiitake mushrooms. Chapters cover shiitakes used in folk medicine for controlling cholesterol, cancer prevention, treating viruses and chronic fatigue syndrome.

Widely available for $9.95.

Web sites: shiitake

The Ohio State University Extension Office features a series of on-line fact sheets that detail shiitake cultivation.

Growing Shiitake Mushrooms (Lentinus edodes ) in Florida

The University of Florida Cooperative Extension Service offers a detailed guide on growing shiitakes in a warmer climate. Covers procedures, requisite supplies and resources, problems encountered, and marketing efforts.

Growing Shiitake Mushrooms
http://osuextra.okstate.edu/pdfs/F-5029web.pdf (PDF / 475 kb) Download Acrobat Reader

From the Oklahoma Cooperative Extension Service, this factsheet offers an overview of shiitake cultivation suitable to hardwood forests of east and central Oklahoma.

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Spawn and equipment suppliers

[This list is not comprehensive and does not imply endorsement of these companies.]

Amycel Spawn
P.O. Box 560
Avondale, PA 19311
800-795-1657 or 800-995-4269 (toll-free)

5050 Greenwich Road
Seville, OH 44273-9413
330-769-2616 FAX

Fungi Perfecti
P.O. Box 7634
Olympia, WA 98507

Gourmet Mushroom Products
P. O. Box 515 IP
Graton, CA 95444
707-823-9091 FAX

L.F. Lambert Spawn Co.
1507 Valley Rd.
Coatesville, PA 19320

P.O. Box 220
560 Farm Rd.
Summertown, TN 38483

Sylvan Spawn Laboratory
West Hills Industrial Park
Kittanning, PA 16201
800-323-4857 (toll-free) or 724-543-2242

UNICORN Imp. & Mfg. Corp.
113 Highway 24
Commerce, Texas 75429 USA
800-888-0811 (toll-free)

Choice Edibles
84 Riverside Park Road
Carlotta, CA 95528

Field & Forest Products
N3296 Kozuzek Rd.
Peshtigo, WI 54157
800-792-6220 (toll-free)

Garden City Fungi
P.O. Box 1591
Missoula, MT 59806

Hardscrabble Enterprises, Inc.
P.O. Box 1124 (or 617 N. Main St.)
Franklin, WV 26807
Contact: Paul Goland

Northwest Mycological Consultants
702 NW 4th St.
Corvallis, OR 97330

J.B. Swayne Spawn Co.
P.O. Box 618
Kennett Square, PA 19348

Western Biologicals, Ltd.
P.O. Box 283
Aldergrove, BC V4W 2T8
604-856-3339 (telephone or FAX)