How to grow shiitake?

Cultivation and harvesting of mushrooms

Mushroom cultivation is a technical process. As mushroom professionals often talk in a technical language, a few of these terms will first be explained.

In the early years of mushroom culture in the Netherlands, compost was scooped into the mushroom trays and then inoculated with spores. A nine week wait followed, until the mycelium spawned sufficiently, flushing started and the grown mushrooms could be harvested by hand.

The cultivation process hasn’t changed that much, but the way the successive steps are performed differ immensely. Hardly anything is done by hand anymore in modern mushroom farming. These changes started to take place when three young mushroom growers from Mook set up the ‘Coöperatieve Nederlandse Champignonkwekersvereniging’ (Cooperative Dutch Mushroom Growers Association: CNC) in 1953. One of their activities was to organize the preparation of compost, resulting in the delivery of ready prepared compost permeated with spawn to most mushroom growers’ doors. Mushroom cultivation can be divided into five phases:

Phase 1: Composting

The growing cycle of mushrooms starts with compost. Compost preparation starts with horse manure. The compost factories get the horse manure from large horse breeding companies that pay the compost factories to collect the manure. Straw, gypsum, chicken manure and water are added to the horse manure. The straw improves the structure, gypsum ensures the proper acidity and the two manures are the nutrients. The compost is produced in tunnels in order to prevent the smell from becoming a nuisance. As manure emits ammonia, compost factories purify the air with ammonia wash to prevent the emission of gases. The indoor fresh compost looks like earth from a forest. Dark brown, full of trampled bits of straw. The compost is steaming, due to the composting process: heat is generated which digests the components. What’s left is a very fertile, nutritious source for mushrooms. On one batch of compost, two to three flushes of mushrooms can be grown. A square metre of compost (which is equal to 90 kilos) yields a maximum of 35 kilos of mushrooms. After that it’s no longer lucrative to reuse the compost. The leftover compost can still be used as a soil conditioner in other agricultural companies.

The largest producer of mushroom compost in Europe is Walkro, with production facilities in Belgium, Germany and the Netherlands.

Richters InfoSheet D8655

Shiitake Mushroom Kit Growing Instructions

The shiitake mushroom (Lentinus edodes) prefers cool temperatures (45-70 degrees Fahrenheit, 7-21 degrees Celsius), and a high humidity (75-85% relative humidity). It requires light – direct sunlight is too strong, but “skylight”, or light from a fluorescent lamp up to about 15 ft. away, is fine. It requires fresh air, but, a lot of air movement will tend to be too drying and may sweep away too much of the carbon dioxide produced by the growing mycelium.

In a less than perfect environment, it is beneficial to keep the bag on the substrate block as much as possible, to minimize the drying and maintain slightly elevated carbon dioxide levels. Open the top of the bag a little, to allow for increased ventilation which helps to induce fruiting (“pinning”) but minimize drying. The substrate surface should be moist at the times when flushes of mushrooms are wanted. When small mushrooms are evident, open the op of the bag a little more. As the mushrooms develop a little more, slit the bag down the sides of the substrate block to provide room for the expanding mushrooms and to provide more ventilation. If mushrooms appear down the sides of the block under the plastic, then slit the bag at that point, but do not cut the surface of any developing mushrooms or the surface of the block.

During damp, cool weather they will grow well outdoors, if protected from direct sunlight, hard freezing, slugs, snails and crawling insects. Forced air heating or a drafty location indoors may cause excessive drying. Constructing a “tent”, in the form of a large, clear plastic bag placed loosely over the top, or poly supported by wire or sticks may be necessary. When dry conditions prevail, you may need to mist the inside of the tent (remember that cold weather outside may result in low humidity indoors). As a method of keeping your mushrooms humid, frequent misting directly onto them is not a very satisfactory approach and often leads to bacterial problems.

Although they may benefit from an occasional drenching, mushrooms must not remain continuously wet, or they will rot. Often, drenching the pack by holding it under a tepid shower for a minute or two at the start is beneficial. Mushrooms should be ready to harvest in 2-3 weeks. After a heavy harvest the block will have lost much moisture. The water may be replenished by immersing the block in cold (35-50 degrees F) water for 4-8 hours. The soaking water should be as cold as possible. Immersion in warm water for more than a short time may damage your mushroom plant. Warm water does not carry as much dissolved oxygen as cold water and at the same time the mushroom’s need for oxygen is greater in warm water. Drain the block well, and place it in a clear poly bag with about ten 1/4″ holes in it, so that it will have a little fresh air and slowly dry out. More mushrooms should appear within 2-4 weeks. If none appear, fruiting may be encouraged by thumping the block down 3 or 4 times on a table. The open the bag for increased ventilation. The reactivation cycle may be repeated 3 or 4 times or more.

Soaking or thumping is sometimes necessary to start the mushrooms initially, if the block has dried out too much before you start to fruit it. Soak in very cold water (a long soak in warm water will damage your mushroom plant) for 4-8 hours. If the surface of your mushroom block is mostly white coloured when you receive it, then it may need to “mature” for a few weeks before it will be ready to brown. Maturing occurs under normal fruiting conditions (55 to 75 degrees F). Some light is essential for maturation. Shiitake mushroom mycelium will be killed at a temperature of about 100 degrees F (just above body temperature), so be careful during hot weather and do not place your plant in direct mid-day sun. Freezing temperature should not damage your shiitake plant unless it is very wet – such as when we ship it to you. If the block has lost a lot of moisture while it matures, it will likely be necessary to soak it.

The Shiitake has an excellent flavour and texture, reminiscent of meat. It makes an excellent addition to soups, stews, stir fries, etc. Dried shiitake chips are a real treat, although strong flavoured. Harvest when white, cottony veil beneath the cap has fully broken away from the stem or, if you want really large mushrooms just let them grow. The substrate on which your mushrooms are growing is made of hardwood dust supplemented with millet grain, rye grain, wheat bran and crushed limestone. No pesticides or chemicals have been added to the medium.

During warm weather, mushroom flies can be a problem. Scraping off any patches in which the larvae are observed will help to control them.

Please Note

This shiitake spawn requires a pre-incubation period of approximately 3 weeks at a temperature of 60-75 degrees F, with some exposure to (low level) light, in as clean a place, prior to fruiting. Humidity is not usually a problem at this stage as the poly bag protects the clock of substrate from drying. However, damp dirty environments often have populations of mites and insects which may infest your fit. During this period the block of sawdust-wood chip substrate will develop patches of brown as it matures. Towards the end of pre-incubation, the sides of the clock will also develop bumps and cracks.

If mushrooms have not started to develop by about 5 weeks, then give the bag a light thumping on a counter top and handle for fruiting as described in the instructions. Temperature changes within the range of about 50-65 degrees F will help to promote “pinning” at this stage. The optimum temperature for colonization and maturing (65-75 degrees F) is a little high for “pinning: (initiation of the fruiting process), and the block should be placed in an environment with a temperature in the range of 45-65 degrees F for pinning and fruiting. high humidity (65-85% relative humidity) is necessary at this stage. Giving the substrate block a thump on the table top will also promote pinning. If mushrooms start to form under the bag, then slit the bag down to that point to allow the mushrooms to expand. Be careful not to cut the developing mushrooms.

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D8655 ©2000 Otto Richter and Sons Limited

The Shiitake is one of the world’s favorite mushrooms.
Common Name: Shiitake Mushroom
Other Names: Chinese forest mushroom, Golden oak mushroom, Oriental black mushroom, Emperors Mushroom
Scientific Name: Lentinula edodes (previously known as Tricholomopsis edodes)
Family: Marasmiaceae (Basidiomycete fungi with white spores)
Given the right conditions, Shiitake can be quite prolific.
Description: Fruiting body with a golden, brown, to almost black, slightly convex cap with a range in diameter of 2-4 inches. The flesh is aromatic, thick, and “meaty”.
Mushroom Niche: Decomposer Natural Culture Medium: Logs
History:

  • A native to eastern China, Japan, and Korea and raised there for over 1,000 years, although it has been used for food and medicine since prehistoric times.
  • Shiitake mushrooms have only been available in the U.S. since 1940.

Trivia:

  • The name Shiitake comes from the Japanese shii take meaning “shii mushroom”… Shii is a Japanese tree (Castanopsis cuspidata) related to the oak and beech.
  • About 160,000 metric tons are produced in Japan each year (over $2 billon worth)

Dried Shiitake are great to cook and store for at least a year.
General “Mushroom” Vocabulary

  • Mushroom – spore-bearing fruiting body of a fungus
  • Fruiting-body – what is commonly called a “mushroom”… the spore-bearing reproductive structure of a fungus
  • Hyphae – vegetative part of the fungus… will develop a fruiting body to reproduce
  • Mycelium (mycelia is plural) – a mass of hyphae is
  • Spawn – material that contains actively growing hyphae of the fungus. Spawn can be used to inoculate the desired culture substrate (logs, branches, stumps, sawdust, etc.) for people to produce a crop of fruiting bodies/mushrooms
  • Stipe – the stem/stalk of the fruiting body/mushroom
  • Pileus – the cap or cap-like structure on top of the stem that supports the spore bearing surface
  • Lamella – the gills (aka ribs) on the undersurface of some fruiting bodies/mushrooms
  • Pores – spongy material with “holes” in it on the undersurface of some fruiting bodies/mushrooms… some mushrooms have these instead of gills

Shiitake love oak wood.
USING THIS MUSHROOM
Primary Uses:

  • Fresh eating (in small amounts)
  • Cooked (steamed, fried, sautéed, simmered, etc.)
  • Dried
  • Tea
  • Pickled

Secondary Uses:

  • Decomposition of “waste” wood 3-6 inches (7.5-15 cm) in diameter which is typically to small for lumber use
  • Medicinal – Animal studies have shown some positive results regarding the antitumor, cholesterol-lowering, and virus-inhibiting effects of several active compounds in shiitake mushrooms. There have been limited studies in humans. I am very interested in this research!

Harvesting: Usually two flushes per year in Spring and Fall. Harvest daily, in the afternoon, by twisting or cutting the base. Look for mushrooms that are firm, plump, clean, and with caps opened 60-75%. Those that are wrinkled, have wet slimy spots, or evidence of pest infestation should be discarded after soaking in water for at least 24 hrs (to break any possible pest life cycle).
Storage: The best way to store loose shiitake mushrooms is to keep them in the refrigerator in a loosely closed paper bag. They will keep fresh at room temperature for just under a week, and in the refrigerator for just under 3 weeks (ideally). Dried mushrooms should be stored in a tightly sealed container in either the refrigerator or freezer where they will stay fresh for six months to one year… although I have bags of dried Shiitake that are still good after many years in storage.
Logs are probably the easiest substrate on which to grow Shiitake.
CULTIVATING THIS MUSHROOM
Cultivation Substrate: Grows on many Broadleaf/Deciduous Trees – log, branch, stump, or sawdust. The following list are woods on which Shiitake reportedly grows:

  • Oak (preferred)
  • Alder
  • Ash
  • Aspen
  • Beech
  • Birch
  • Chestnut
  • Cottonwood
  • Eucalyptus
  • Hickory
  • Ironwood/Hornbeam
  • Pecan
  • Poplar
  • Sweetgum (preferred)
  • Willow

Preparing the Culture Medium: Logs are ideally harvested from live, healthy trees in winter when there are a lot of stored carbohydrates. Diameter 3-6 inches (7.5-15 cm) and length 3-5 feet (0.9-1.5 meters), although length is really based on what can be easily handled. Bark is left intact. Inoculation of the logs should take place 2-4 weeks after cutting to allow enough time for the natural anti-fungals to break down but not enough time for other fungi to start colonization.
Hammering the spawn plugs into place.
Spawn Details:
It is recommended that at least two strains of spawn be used to provide the best chance of success. Consider one that is tolerant of cold weather and one tolerant of warm weather.
Spawn Available:

  • Hardwood Plugs – dowels inoculated with mushroom spawn that are hammered in holes (typically 5/16 inch diameter, about an inch deep, and about 2 inches apart) drilled in logs, branches, or stumps
  • Sawdust Spawn – sawdust inoculated with mushroom spawn that is placed into holes or notches cut in branches or logs; can be sprinkled on piles of sawdust (substrate) but may need a ratio as high as 3:1 (by volume, substrate:spawn) to minimize competition from other fungi

This is a common staking method for Shiitake logs.
Incubation of Logs:
Stack logs close together for the first two months. This helps conserve moisture. If the logs become too dry, then constant watering or soaking for 48 hrs is needed. Allow for good air circulation between the logs. Providing shade (50-75% depending on local conditions) will help keep the moisture balance correct.
Shiitake ready for harvest!
FRUITING CONDITIONS FOR THIS MUSHROOM Fruiting Temperature: 50-80 F (10-27 C) Moisture: Sustained moisture required for fruiting (wood moisture content of 35-45%). Bark should be dry but the wood underneath should be moist. Induction of Fruiting: Typically 2 weeks after a natural rainfall; may be induced by soaking logs in cool water for 1-3 days… check with the supplier of the strain you are using for more details.
Life Span: Time to Begin Fruiting: 6 months to 2 years Years to Maximum Fruiting: 1-2 years Years of Useful Life: Varies on the density of the wood (oak is very dense), the thickness of the log, and the conditions in which the mushroom substrate is kept, but 6+ years is not uncommon
Shiitake on the left and Oysters on the right… growing in my bathroom… Yeah, my wife wasn’t real crazy about this! 🙂
ADDITIONAL INFORMATION ON THIS MUSHROOM
Nutritional Information
Concerns:

  • Approximately 1 in 50 people will develop “Shiitake Dermatitis”, an itchy rash that develops within 48 hrs of eating raw or undercooked shitake mushrooms. The rash lasts about 10 days and is caused by the long-chain carbohydrate molecule “lentinan” which is destroyed by heat.
  • If you have gout or kidney disease, you may want to avoid eating a lot of mushrooms since they contain concentrated levels of purines.

Growing Shiitake Mushrooms: Step-by-Step Guide to an Agroforestry Crop

Photo by Taylor F. Lockwood

Ah, mushrooms. For the wild mushroom hunter, making a fungi foray into a forest erupting with golden chanterelles, bursting with radiant oyster mushrooms, and scattered with black trumpets is like finding heaven itself. Days like these aren’t typical, however, and when you have a hankering to cook fresh mushrooms, you’ve probably found that most appetizing mushrooms – from morels to shiitakes – fetch a high price at farmer’s markets and specialty shops. But fortunately there’s another way to procure delectable gourmet mushrooms: grow them yourself.

Shiitake mushrooms, Lentinula edodes, have been grown in Japan for over 2,000 years. Shiitake are low in cholesterol, high in B vitamins, and have an exquisite taste. Their popularity as a valuable gourmet mushroom, as well as their reputation for having health benefits, is growing in this country as well. To supply the burgeoning market for shiitakes, forest owners in the United States are cultivating them in their woodlots as an agroforestry crop.

The name shiitake means “mushroom of the oak,” but shiitake mushrooms will also grow on sugar maple, hophornbeam, ironwood, alder, poplars, and yellow birch. Still, the mycelium’s favorite food for producing a flush of lovely brown shiitake caps is oak, either white or red.

Growing shiitake mushrooms as a forest product takes a bit of brawn and mycological know-how, but if you have a fondness for fungi and some hardwoods in need of thinning, this might be your most satisfying side business yet. That’s what shiitake grower Ithaca Farmer’s Market and to several area restaurants. With their forest mushrooms in such high demand, they plan on expanding their production. Each log inoculated has the potential of re-flushing for three years or more. According to Sierigk, “depending on the size of your logs, you can expect about a pound of mushrooms per log per year.”

Although Sierigk recommends starting small until you get the hang of it, Teresa Vanek and Brant Welch of Cornell Cooperative Extension, it’s okay to harvest logs as late as March for an April inoculation.

You should not inoculate right after cutting. Tree sapwood contains natural defenses against fungal invasion, including phytoalexin-like compounds called coumarins, that accumulate in the vicinity of wounding within 24 hours and continue increasing in concentration for the next few days. Because of this, it’s best to wait a minimum of three days to allow the compounds to disperse before inoculating the logs. “The rationale is to wait a week or two after harvest for antifungal agents in the logs to decline,” Ochterski said. Don’t wait much longer than that, because you want to make sure that other fungi don’t get a head start.

You can experiment with fall cutting and inoculation. Ochterski stresses that “there’s still not enough information on the physiology involved or the timing of harvests.” Growers in northern climes have had success inoculating as late as October. In any case, you should avoid the hot months of summer.

Mushroom spawn comes in a variety of forms. Two of the more common are wooden dowel plugs, above, and a sawdust mixture, below. Photos by George Vaughan.

Mushroom Spawn

Shiitake mushroom spawn can be ordered from a specialty mushroom farm online or through the mail (see below for sources). Those with a mycological touch can even raise their own. Spawn generally comes either impregnated in wooden dowel plugs, in liquid form, or mixed with sawdust. The spawn is mushroom mycelium, the threadlike, non-fruiting part of the fungus that colonizes a log and eventually bears mushrooms. If mushrooms were apples, the mycelium would be the tree they grew on. The mycelium will eventually invade an entire log, showing white at either end when the log is fully colonized. Just prior to fruiting, a flush of small nodes, called pins, will be seen under the bark before the mushrooms themselves emerge.

The whole process from inoculation to fruit will take as little as four months or more than a year, depending on the strain of mycelium used, the weather conditions, and the moisture in the log. Several strains of shiitake are available for purchase: cold weather, warm weather, and wide range. Most growers recommend trying all three strains to determine what works best for your area and your market.

Plugs and sawdust are the most common inoculation techniques. For plugs, use a 5/16-inch bit to drill holes that are one inch deep, then gently hammer in the plugs. If using sawdust, use a 3/8-inch drill bit and drill to a depth of 11/4 inches before pressing in the sawdust. Plugs are easier to handle and apply, while sawdust produces better colonization if it’s kept moist. In either case, holes are generally drilled at 10-inch intervals down the length of the log. Spin the log to provide a gap of two inches between rows, and stagger the holes from one row to the next.

Many growers seal the holes with melted paraffin wax, which helps hold moisture in and keep wild fungal invaders out. Some growers also seal both ends of their logs for additional moisture retention. Use a wood moisture meter to monitor your logs for proper moisture content: between 35 and 45 percent is optimal for a successful harvest.

A criss-cross log pattern, below, works well. The traditional X pattern, above, makes harvesting easy but isn’t the best position for maintaining moisture balance in the logs. Photos by Angela Cannon-Crothers.

Stacking Logs in a Bedding Area

The bedding area for logs that have been inoculated with mushroom spawn should be well shaded and protected from wind, which will dry the logs. To conserve moisture in your logs, stack them close together and close to the ground, with space for minimal air circulation underneath. Choice bedding areas include hemlock and spruce stands, under hardwood trees, or even under shade cloths. A criss-cross, box pattern works well, as does slope-stacking down a hill in a cribwork. Some growers prefer to string a strong wire between two trees and lean the logs against the wire from either side, creating an X pattern. This method works well for ease of picking, but isn’t best for maintaining moisture balance in the logs.

Preparing For Harvest

Watering at regular intervals – weekly in drier areas where a drenching rain hasn’t recently occurred – is critical. You can either bring water to the logs or the logs to water. Some growers use 500- gallon livestock tanks, a pond, or a creek. You should soak your logs for 24- to 36-hour intervals – or until the logs stop forming bubbles and show signs of complete saturation. If you are going to use a soak tank, you’ll probably need a tractor to move heavy wet logs. The alternative to a soak tank is to use some form of irrigation or overhead watering system to drench the logs in place.

Soaking logs can force fruiting once mycelium is visible on log ends, or when pinning has occurred, but isn’t recommended once the mushrooms are visible. At this point, indirect sunlight can be beneficial to help fruiting. Some growers pound on their logs with a heavy bar to help encourage fruiting.

Because of the high moisture levels required for fruiting, mushroom bedding areas need some sort of control to prevent slugs from eating the budding fruit. Options include a gravel ground cover throughout the bedding area, pans of beer to drown the gastropods, or a circle of iron oxide that is refreshed as needed to create a barricade. Sierigk and other growers employ all three methods.

Once the mushroom caps begin to emerge, you may need rodent deterrents to keep chipmunks at bay.

The Harvest

At full fruit stage, the shiitake has a cap that is maroon-brown and speckled with lovely gem-like dots around the rim. Different strains vary to some degree, so learn to properly identify them. Gently break the stems off the logs and place them in cardboard boxes or paper bags. Once picked, the mushrooms will only stay fresh for a couple of days during hot weather. With refrigeration, they can keep for two to three weeks. If you can’t bring your crop to market in time, the mushrooms can be dried in a dehydrator or on screens in a greenhouse and packed for later sale. Dry shiitakes reconstitute well and still command a good price.

Establishing your market is best done prior to harvest. Try forcing a log or two ahead of time in a soak tank and taking these mushrooms to nearby restaurants, farmer’s markets, or specialty stores as samples. Fresh shiitake sell for about $16 a pound, depending on your area. Wild mushrooms, such as chanterelles, black trumpets, and hen-of-the-woods (maitake), go for around the same price. Whether you’re collecting mushrooms in the wild or farming them in your woodlot, you should never put mushrooms into plastic bags or they will quickly rot.

Whether you intend to grow shiitake mushrooms on a large scale or just for your own table, the process requires some work and plenty of patience, but the rewards are delectable. While the extravagant health benefits attributed to homegrown shiitakes – they’re said to boost the immune system, regulate diabetes, and combat cancer – are not scientifically proven, one thing is for sure: they’re all natural and very tasty.

Mushroom Spawn & Supplies

Mushroom Harvest
PO Box 584, Athens, OH, 45701
Phone: (740) 448-7376
Fax: (740) 448-8007
Email

Mushroom People
560 Farm Road, Summertown, TN, 38483
Email
Order Phone: (800) 692-6329 11-6 p.m. CST, M-F

Fungi Perfecti
PO Box 7634, Olympia, WA 98507
Phone: (800) 780-9126 / (360) 426-9292

For Further Reading

Growing Shiitake Commercially, by Bob Harris

The Mushroom Cultivator, by Paul Stamets and J.S. Chilton

Shiitake Grower’s Handbook: The Art and Science of Mushroom Cultivation, by Paul Przybylowicz and John Donoghue

Angela Cannon-Crothers is an environmental educator and writer in the Finger Lakes Region of New York.

Shiitake – “Straw”-strain – Lentinula edodes – Grain Spawn

This Shiitake strain is special as it is growing well on straw. This makes it suitable for cultivation on straw-bales, unlike most other Shiitake strains. The “straw”-strain belongs to the shiitake with colder fruiting temperature (14 – 16 ° Celsius). It may also fruit at higher temperatures, but this is not optimal and might lead to not as nicely developed fruit bodies.
The Japanese name Shiitake consists of the words Take (= mushroom) and Shii (= Pasania-tree) and means mushroom that grows on a tree. The Shiitake has originally been domiciled in Japan, Korea and China and his special characteristics are known by the people for more than 2000 years. The smell of this special mushroom is very similar to garlic and is due to an ingredient called Lenthionine. Shiitake counts to the most popular gourmet-mushrooms in the world.
You receive ready colonised rye grain spawn for inoculation of convenient fruiting substrate. Larger quantities for commercial mushroom growing on request. Recommended only for experienced cultivators!
Production time: Spawn is made fresh after ordering, production time 2 to 3 weeks.
This product is fresh produce and should be processed immediatly after delivery.
If the product cannot be processed immediatley, it can be stored in the fridge at 4° Celsius for a maximum of two weeks.
Please choose:

Organic Shiitake – “Straw”-strain – Lentinula edodes – Grain Spawn small

Mastergrain (rye based)
Certified for organic mushroom cultivation.
(Organic control station: AT-BIO-701, Biko Tyrol)
1 autoclavebag approx. 1.6 kg – 2.5 liter
Price: from 14.90 €

Organic Shiitake – “Straw”-strain – Lentinula edodes – Grain Spawn large

Mastergrain (rye based)
Certified for organic mushroom cultivation.
(Organic control station: AT-BIO-701, Biko Tyrol)
1 autoclavebag approx. 3.3 kg – 6 liter
Price: from 19.90 €
Suitable Substrate:
hardwood (most suitable: oak, beech, birch, alder, chestnut, pasania), straw
Suitable method of cultivation:
wood logs, mushroom bed / patch, indoor mycelium bags for cultivation in a greenhouse, cultivation on bales of straw is still under research
Taxonomy:
Kingdom: Fungi
Division: Agaricomycetes
Class: Agaricomycetidae
Order: Agaricales
Family: Marasmiaceae
Genus: Lentinula
Species: Lentinula edodes
Spores: white, ovoid to ellipsoid, 5 – 6.5 x 3 – 3.5 µ
Growing conditions:
Phase 1: Mycelium growth
Temperature: 23 – 26°C
Humidity: 95 – 100%
Duration: 8 – 10 weeks
CO2: >10,000 ppm
Fresh air exchange: 0 – 1 per hour
Light: 50 – 100 lux
Phase 2: Primordia formation / Fruiting initiation
Temperature: 17 – 19°C
Humidity: 95 – 100%
Duration: 5 – 7 days
CO2: <1,000 ppm
Fresh air exchange: 4 – 7 per hour
Light: 500 – 2.000 lux
Phase 3: Fruiting and Harvest
Temperature: 14 – 17 °C
Humidity: 85 – 95%
Duration: 5 – 8 days
CO2: 600 – 1,000 ppm
Fresh air exchange: 5 – 8 per hour
Light: daylight (12 h cycle)
Cropping cycle: 2 – 3 crops, about 2 weeks apart

Once the straw is cool, it is inoculated with grain spawn by simply mixing the spawn evenly into the straw. One basket of pasteurized straw usually weighs about 60lbs. The straw must be inoculated with an adequate amount of spawn to insure that the straw will be colonized within 7 to 10 days. If the straw is not colonized within that time period, spores that survived pasteurization might germinate and contaminate the straw. Some growers inoculate at a low rate of one 5 lb bag of grain spawn to 160 lbs of pastuerized straw, which can fill four bags with a height of 4′ and a diameter of 12″. A heavier inoculation rate of one 5 lb bag of grain spawn to one 40 lb straw bag, usually results in much lower contamination rates and significantly higher yields. The inoculated straw is stuffed into plastic bags that will either be hung from the ceiling or that will rest on a support. The bags must be packed tightly so that the straw will be pressed up against the plastic bag. If the bags are to hang in the air, they must have a thickness of 4 mil. Typically, cylindrical bags with a 12″ diameter and a length of 4′ to 12′ are used. A 4′ bag with a diameter of 12″ weighs between 40 lbs. to 50 lbs. when filled with inoculated straw.

PMC

Results and Discussion

After the incubation period, substrates showed dark colored patches that eventually spread to cover the entire surface. This is consistent with its appearance cited by Przybylowicz and Donoghue (1990). The exudate indicated the maturing of the mycelium, a state that is adequate for fruiting (Donoghue and Denison, 1995).

Regarding the formula of the spawn used during the incubation period, no time difference was observed for the colonization of the substrate to take place. Table 1 shows the effect of the inoculated substrate for each spawn formula employed during the total mushroom production period (PP) for each strain evaluated. The PP differed significantly among strains (F = 28.46, df = 3, p = 0.001), formula (F = 120.36, df = 2, p = 0.001) and their interactions (F = 24.68, df = 6, p = 0.001). The PP varied between 34 and 56 d depending on the strain and spawn formulation used. However, the total weight of fresh mushrooms of two harvests was greatest for F1 (p < 0.05). In general, the wheat straw inoculated with formula 1 and 2 produced greater yields than that inoculated with the control (C). The longest periods of production were observed for substrates inoculated with F1 (IE-40, 42 d), F1 (IE-105, 49 d), F2 (IE-124, 56 d) and F2 (IE-256, 49 d) (Table 1). Mushroom yields were significantly affected by strain (F = 28.46, df = 3, p = 0.001), formula (F = 120.36, df = 2, p = 0.001) and their interactions (F = 24.68, df = 6, p = 0.001). The total production of fresh mushrooms produced varied between 437.7 (C-IE-40) to 1952.9 g (F1-IE-124) (p < 0.05). The number of harvests obtained for all the strains from the inoculated substrate using each formula was two. In general, 50% to 72% of the total production was obtained during the first harvest. The highest production percentage observed for the first harvest was that of the substrate inoculated with the supplemented spawn (Table 1).

Table 1

1Production Period (time from primordia formation to last harvest). 2Fresh weight of mushrooms harvested from ten replicates. 3Distribution of total weight mushrooms obtained in each harvest, estimated in percentage. 4Means ± standard deviation followed by different letters indicates significant differences according to Duncan (p < 0.05).

Mushroom yields per size group during the first and second harvest were significantly affected by strain and formula (Table 2). Mushrooms produced from the substrate inoculated with control (C) spawn were mainly of three sizes, with the exception of the IE-124 strain that also produced a size G4. Mushrooms of G2 and G3 sizes were predominant in the first and second harvests. The greatest presence of G2 in the substrate inoculated with C was for strain IE-105 (60.3%) and strain IE-256 (53.1%) for the first harvest, whilst these same strains produced mainly G3 mushrooms in the second harvest: 64.7% and 62.3%, respectively. Substrate inoculated with C (all strains) averaged 84% of the total production for G2 and G3 during the first and second harvesting cycles. Substrate inoculated with F1 yielded mushrooms in all four groups, with the exception of IE-105 which did not produce G4 mushrooms during the first harvest and IE-256 which did not produce G4 mushrooms in the first or second harvest. Strain IE-124 did not produce mushrooms of G1 size in either harvest but developed abundant mushrooms of the remaining groups. The predominant production corresponded to G2 and G3 mushrooms in the first harvest and G3 and G4 in the second (p < 0.05). The greatest presence of G2 mushrooms in the substrate inoculated with F1 in the first harvest was for IE-105 (60.8%) and IE-256 (59.0%) (p < 0.05). These same strains produced mainly G3 mushrooms in the second harvest: 49.59% and 49.88%, respectively. The IE-124 strain stands out in both harvests where it generated more than 55% G4 mushrooms (> 15 cm). The substrate inoculated with F1 yielded 66% of G2 and G3 mushrooms in the first harvest and more than 68% G3 and G4 in the second.

Table 2

P-values from analysis of variance (ANOVA) for mushroom size of Lentinula edodes harvested from pasteurized wheat straw inoculated with the control, formula 1 and formula 2.

First harvest
Effect DF F p*
Strain 3 4.27 0.0056
Formula 2 28.99 0.0001
Size 3 68.99 0.0001
Strain × Formula 6 5.56 0.0001
Strain × Size 9 23.69 0.0001
Formula × Size 6 4.91 0.0001
Strain × Formula × Size 18 4.12 0.0001
Second harvest
Strain 3 25.71 0.0001
Formula 2 31.72 0.0001
Size 3 81.40 0.0001
Strain × Formula 6 11.68 0.0001
Strain × Size 9 14.09 0.0001
Formula × Size 6 7.91 0.0001
Strain × Formula × Size 18 7.83 0.0001

*p values < 0.05 were considered significant.

Substrate inoculated with F2 produced mushrooms mainly of three sizes in the first harvest, with the exception of the IE-124 strain which produced G4 mushrooms, whilst in the case of the second harvest, all strains developed mushrooms of four sizes with the exception of IE-256 strain which did not produce G4 mushrooms. IE-105 did not produce G1 mushrooms but the best represented groups sizes were from G2 to G4. The predominant production of all strains corresponded to G2 and G3 for both harvests. A greater presence of G2 mushrooms for the first harvest was observed for IE-105 (56.6%) and IE-256 (45.4%), but 52.2% of G4 mushrooms was also recorded for IE-40. For IE-105, 40.6% of G4 mushrooms were produced in the second harvest while IE-256 produced 44.1% of the G3 category. IE-124 strain stands out as producing mushrooms of G4 size in both harvests, 34.4% in the first and 28.8% in the second. In general, the groups with the greatest representation were G2 and G3 with the larger size corresponding to the substrate inoculated with F1 and F2, F1 producing more G4 mushrooms.

Table 3

Biological efficiency (%) of Lentinula edodes strains on pasteurized wheat straw inoculated with three types of spawn.

Values are mean ± standard deviation. Means that do not have at least one letter in common of each strain in three formulae and only among means are significantly different (Tukey p < 0.05).

Table 4

Production rate (%) of Lentinula edodes strains on pasteurized wheat straw inoculated with three types of spawn.

Values are mean and ± are standard deviations. Means that do not have at least one letter in common of each strain in three formulae and only among means are significantly different (Tukey p < 0.05).

Previous studies report shiitake cultivation on wheat straw. Mata et al. (1998) used wheat straw pasteurized at 65 °C and supplemented. In that study, BE was 38% and 44%. However, Savoie et al. (2000) obtained a BE of approximately 60% using pasteurized wheat straw and Gaitán-Hernández and Mata (2004) reported a BE of 46.9% and 50% when they used two strains of shiitake on wheat straw, in this case pasteurizing through hot water immersion. Gaitán-Hernández et al. (2006) used sterilized wheat and barley straw in the cultivation of four shiitake strains. In that study, BE of 49% in wheat straw and 77% in barley straw were obtained. In the present higher BE were reached utilizing pasteurized substrate and supplemented spawn. The BE values reported in previous studies vary according to the strain, substrate, supplements and treatments used (Mata and Gaitán-Hernández, 1994; Salmones et al., 1999; Leifa et al., 2000; Morais et al., 2000; Pire et al., 2001; Philippoussis et al., 2003, 2007; Rossi et al., 2003; Fung et al., 2005). Nevertheless, very few studies have been carried out to improve the spawn and prove its effect in the growth and production of shiitake (Royse, 1996; Mata et al., 2002).

The average PR reported in our study are higher than those cited by Gaitán-Hernández et al. (2006) in shiitake cultivated on barley straw and sterile wheat straw: 1.1% and 0.6%, respectively. On the other hand Royse (1985) reported PRs of 0.2% and 0.7% when shiitake was grown on enriched sterile sawdust.

Table 5

Yield (%)1 of Lentinula edodes strains on pasteurized wheat straw inoculated with three types of spawn.

In the present work higher BE, PR and Y were reached utilizing pasteurized substrate and supplemented spawn. The reason for this remains unknown, but may be related to the supplementation with nutrient added at each spawn type (wheat bran, powdered wheat straw). On the other hand, the strain’s capacity to invade this substrate is related to the shiitake’s strain adaptation to the particular system.

Mature fruiting bodies produced on the substrate inoculated with each spawn formulation show a normal development and morphology. The proximate composition of the fruiting bodies of Lentinula edodes was significantly affected by strain and formula (Table 6, ​,7).7). The protein content was high, particularly in the case of F1-IE-40 and F1-IE-105 showing a positive correlation in its biological efficiency (r2 = 0.74). These results coincide with those registered by Salmones et al. (1999) and Morais et al. (2000) for fruiting bodies obtained from different sterile substrates, as well as those cited by Philippoussus et al. (2007) for mushrooms harvested from sterile supplemented wheat straw (18% d.w). The ash and raw fat contents were also similar to those reported by Morais et al. (2000) for mushrooms cultivated on sterile wood shavings. A variation in the ash content was observed according to the spawn formulation. However, there were no statistical differences (p > 0.05) for C and F1 for IE-105 or IE-256 strain.

Table 6

Analysis of variance (ANOVA) for the proximate composition of the fruiting bodies of Lentinula edodes harvested from pasteurized wheat straw inoculated with different types of spawns.

Factor Effect DF F p*
Strain 3 3.20 0.0412
Moisture Formula 2 9.13 0.0011
Strain-Formula 3 8.89 0.0001
Strain 3 77.10 0.0001
Ash Formula 2 58.27 0.0001
Strain-Formula 6 94.62 0.0001
Strain 3 42.97 0.0001
Crude fat Formula 2 41.14 0.0001
Strain-Formula 6 19.07 0.0001
Strain 3 32059 0.0001
Crude protein Formula 2 59857 0.0001
Strain-Formula 6 68701 0.0001
Strain 3 18.0 0.0001
Carbohydrates Formula 2 23.9 0.0001
Strain-Formula 6 43.5 0.0001
Strain 3 18.2 0.0001
Energy value Formula 2 6.4 0.0057
Strain-Formula 6 26.9 0.0001

*p values < 0.05 were considered significant.

Table 7

Chemical composition of Lentinula edodes fruiting bodies harvested from pasteurized wheat straw inoculated with three types of spawn (see Table 1).

1F formula; 2M moisture; 3A ash; 4CF crude fat; 5CP crude protein ; 6CH carbohydrates; 7EV energy value . Values are means ± standard deviation of three replicates. Means in a column with different superscripts are significantly different (Tukey p < 0.05). All values are on a dry matter basis, except moisture (percentage of fresh mushroom wt).

The selection of a good spawn adapted to these conditions is critically important to ensure a high production of bodies in the shortest time possible. The bioconversion process of pasteurized wheat straw using a nutritionally supplemented spawn offers the possibility to increase yield and generate an alternative food product containing high percentages of total carbohydrates and proteins with an equivalent or higher nutritional value when compared to other food products.

The research clearly demonstrates the need for well specified strain and spawn combinations for any production and that any farmer needs to carefully evaluate any change to his production practices.

Growing Shiitake Mushrooms

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Growing shiitake mushrooms is the perfect way to get started with homegrown mushrooms. Shiitakes are incredibly easy to grow, which makes them a perfect beginners mushroom. For the more experienced mushroom cultivator, there’s often far more demand than supply, which means they’re a good addition to your farmers market table. A high price tag at the store means that growing shiitake mushrooms pays back quickly, especially since it only takes a small investment to get started.

Our very first shiitake mushroom growing out of a sugar maple log.

Shiitakes produce best on oak logs, and their name actually means “mushroom of the oak.” Our swampy land doesn’t have any native oak trees, and we’re currently cultivating shiitakes on sugar maple thinned from our sugarbush. While they may grow best on oak logs, they still produce great crops on a number of other types of log substrate. Shiitakes can also be grown successfully on sugar maple, hop hornbeam, alder, ash, beech, hickory, poplar and yellow birch.

If you just want the experience of watching them grow and develop, but you don’t have access to a woodlot, try a shiitake mushroom grow log. This is a great option for cultivating shiitakes indoors since everything is self-contained within the growing kit. It’s a great option for people that don’t have ready access to fresh logs.

If you do have access to fresh hardwood logs for shiitake cultivation, choose healthy trees that are free of disease and don’t show evidence of other mushroom colonization. For ease of handling, it’s best to choose relatively small trees, between 4 and 6 inches in diameter. If you’re woodlot is dense with small trees, thinning it for mushroom cultivation is a good use of the wood.

Cut the logs in to 3 to 4 foot lengths to make them easy to handle and stack. Shiitake mushroom logs are often moved, soaked and stacked throughout their productive lifespan to induce fruiting. If you cut your mushroom logs too large, you’ll pay for it with a sore back over the roughly 8-year lifespan of each shiitake log.

Be careful to select logs with fully intact bark. The bark on each growing log will help retain moisture, which is essential for long-term shiitake production. When logs quit producing early, most often it’s because the log dried out too much at some point in its lifespan. The only breaks in the bark should be the holes you drill to install dowel plugs, but then even those will be covered over with wax later to preserve mositure.

Shiitake mushroom plug spawn about to be hammered into a sugar maple log.

Selecting Shiitake Mushroom Spawn

Mushroom spawn is some type of substrate that has been colonized by mushroom mycelium. Generally, shiitake mushroom spawn is purchased as either plug spawn or sawdust spawn.

I’d recommend starting with plug spawn. It’s very easy to work use and requires few special tools. Plug spawn is small dowels that have been inoculated with shiitake mycelium. Sawdust spawn is generally cheaper, but it’s a bit trickier to work with. A special inoculation tool is used to pack the sawdust into holes drilled in your mushroom logs.

A bag of 1000 shiitake mushroom plugs. It takes about 100 plugs for every 2-3 logs. This bag was enough to inoculate 24 logs in an afternoon.

Supplies for Growing Shiitake Mushrooms

To grow shiitake mushrooms, you’ll need just a few things beyond hardwood logs and shiitake mushroom dowel plugs. If you’re starting with an indoor shiitake growing kit, everything’s already prepared for you. For the more hands-on grower hoping to put a substantial quantity of mushrooms on the table, you’ll need the following:

  • 100 Shiitake Mushroom Spawn Plugs for every 2 or 3 logs
  • Food safe wax such as cheese wax, bees wax or refined mushroom wax
  • Hardwood logs (4 to 6 inches in diameter, 3 to 4 feet long)
  • Daubers or a Paint Brush to apply wax
  • 5/16-inch Drill Bit
  • Drill Bit Stop Collar
  • Cordless Electric Drill

For reference, I would highly recommend Tradd Cotter’s book, Organic Mushroom Farming and Mycoremediation. He covers every technical detail you’d need for growing just about any strain of cultivated mushroom. The best part is after he gives you all the super detailed science, he goes through it again in layman’s language, telling you how to do it all in your backyard with minimal tools and equipment.

Growing shiitake mushrooms starts with inoculating hardwood logs. The first step is drilling holes to inoculate the logs with shiitake mushroom spawn. For plug spawn, use a 5/16-inch drill bit to drill 1 inch deep holes. A stop collar attached to the drill bit makes drilling the correct depth easy as you work around your logs. (Sawdust spawn uses a 3/8-inch drill bit and holes 1 1/4 inch deep.)

A stop collar is important because it’s hard to drill holes to a precise depth consistently. If the holes are too deep, the extra space prevents the dowel plugs from effectively colonizing the log. If they’re too shallow, the plug won’t fully seat into the log, which leaves them at risk for drying out. After you’ve drilled 100 or more holes in an afternoon, this extra investment of a few dollars for a stop collar is well worth it.

A 5/16-inch drill bit with a stop collar attached 1 inch up the shank. This is the perfect setup to quickly drill holes for plug spawn.

Holes are drilled at 10-inch intervals down the log, in rows about 2 inches apart. Stagger the rows using a diamond pattern. This helps to ensure that the entire log is colonized with mushroom mycelium. While you could innoculate the logs more densely, this is the recommended amount to ensure full colonization without excessive waste. The most expensive part about growing shiitake mushrooms is the dowl plug spawn and overusing it drives up your costs.

Conversely, while over inoculation can cost you extra money, under inoculation can leave openings for competing fungus. It’s better to go a bit heavy handed on inoculating shiitake logs than to cheap out and try to innoculate extra logs with insufficient dowel plugs.

Holes are spaced about 10 inches apart, in rows 2 inches apart using a diamond pattern.

Once the holes are drilled, place a dowel plug in the hole and use a rubber mallet to gently tap it into place. A hammer works here too, just don’t apply more force than is actually necessary to tap the plug into the wood. Any extra damage to the bark will potentially cause drying which will hurt your shiitake crop down the road.

This is a great time to get the kids involved in growing mushrooms. Our 20-month-old daughter loved playing whack a mole with a rubber mallet and plug spawn, and then she was ecstatic to harvest the fruits of her labor the following year.

Tapping shiitake mushroom plugs into logs with a rubber mallet.

Though it’s not strictly required, most growers use a food-safe wax to seal the plugs and help hold in moisture. Even in a very wet climate up here in Vermont, we’ve still had trouble with logs drying out and quitting production long before their rated lifespan. Good choices are cheese wax, bees wax or specialty refined mushroom waxes that are sold by mushroom supply companies.

This kit comes with both shiitake mushroom plugs and mushroom wax, as well as daubers to apply the wax and tags to label the logs. It’s a good “all in one” place to start.

Some growers also seal both ends of the log with wax to help seal in moisture. This practice is a bit controversial, since when you seal the ends it makes it harder for the log to absorb moisture. If the logs do get too dry, you may not be able to fix it if you’ve sealed the ends. We don’t seal the ends, which allows for more flexibility when you need to water or soak the logs in dry years.

Shiitake mushroom spawn plug sealed with wax.

Tending Shiitake Mushroom Logs

Once you’ve inoculated your logs, they need to be kept sheltered from sun and wind which can dry them out. A low stack in a shaded area that you can reach with a hose is ideal. Like newly planted fruit trees, shiitake mushroom logs require about an inch of rain on average per week and should be supplemented with a hose during dry periods.

In dry areas, water the logs with a sprinkler weekly. This isn’t necessary if you have very regular rains. Our first year we were confident that we “always” get good rain during the summer months. Of course, that year there was a record drought. Error on the safe side and stake the logs in an area that’s easy to reach with a hose.

If you’re in a particularly backwoods location without access to a hose, a body of water works well too. In dry times, the logs can be dropped into the water for a few hours to recharge their reserves.

Most the year, shiitake mushroom logs can be kept stacked “log cabin style” to minimize their footprint. This allows you to fit more logs in a small space, and make it easy to keep the log stack watered during dry times.

Photo Credit Joel Sandin

Shiitake Mushroom Pests

Before fruiting time, the biggest threat to a shiitake cultivation operation is drying out. Once fruiting begins, the concern shifts to predation by slugs. Farming the Woods suggests employing a flock of backyard ducks to keep the slug population down, but when we raised ducks they devastated out landscape after heavy rains. They don’t eat the mushrooms, but they do eat just about everything else, from slugs to greenery, and they make an unholy mess of the muddy land after heavy rains.

A much more reasonable slug prevention tactic is circling the logs in a thick ring of wood ash. The slugs won’t cross a 3-4 inch wide ring of wood ash, as it’s basically made of leftover salts in the wood after burning. Unlike table salt, it won’t hurt the soil or woodland ecology. Wood ash is a great natural slug prevention technique, but just be sure to re-apply after heavy rains.

Harvesting Shiitake Mushrooms

Once the log is fully colonized with mycelium, you can induce fruiting by soaking the logs in a stock tank or giving them a whack. Either whack them with a heavy pipe or baseball bat or pick them up and drop them lengthwise onto their end. The impact helps to stimulate the mycelium to fruit, and both soaking and impact are traditionally used in Japan. By soaking just a small portion of your logs each week, you can stagger harvests over a long fruiting season.

After the logs have been soaked, they’re leaned up against something so they can stand vertically. This allows more of the log to be exposed, which makes it easier to monitor and harvest the mushrooms. After the fruiting period ends, they’re stacked again into log cabin like piles.

Once the mushrooms break the surface of the log, they can be gently broken off by hand. Mushrooms can be used fresh or dried in the sun on a screen for 2 days for long-term storage.

Photo Credit Joel Sandin

Shiitake Mushroom Yields

Shiitake mushroom logs will begin to produce roughly 8 to 16 months after inoculation. The specifics will depend on your climate. Each log will produce about a pound of mushrooms per year for up to 8 years. Shiitake mushrooms sell for about $10 per pound locally, which means that each log should produce roughly $80 worth of mushrooms in its lifespan. A single bag of 100 spawn plugs costs about $10 can innoculate roughly 3 logs. That means a $10 investment (plus an afternoon of work) should result in roughly $240 worth of mushrooms.

Larger commercial operations bring their costs down further by using sawdust spawn and specialized inoculation tools. That said, the biggest cost for a producer is time. The time waiting for the logs to produce, and the time moving, sorting and watering logs. For a backyard producer, your time is “free” if you’re doing this for fun and the profits can be eaten up at home in tasty harvests.

Growing Shiitake Mushrooms at Home

Now you can go back to your other chores for a while, since the cut logs need to cure for 30 to 90 days, or until their moisture content has dropped to 40 or 50 percent. Professional foresters and shiitake cultivators use a special measuring device to determine the moisture content of wood. You can test your stock, though, by cutting about six inches off a log, then cutting a one-inch slice from the new end. Weigh the one-inch piece, then dry it in an oven at 120 degrees Fahrenheit for about 48 hours. (To avoid tying up your oven for that long, you can use a small toaster oven, or simply dry the slice overnight for several nights in a row.) Weigh the wood occasionally, and when it ceases to lose weight, subtract the dry weight from the wet weight to find the weight of water in the log. Then divide the weight of the water by the original wet weight. Then, multiply that figure by 100 and you’ll have the percentage of moisture in the logs.

Inoculating the Logs with Shiitake Spawn

When the moisture content has dropped to 40 or 50 percent, the logs can be inoculated. This is usually done in early spring. About six to eight weeks beforehand, order your spawn plugs — short wooden dowels impregnated with shiitake spawn. If you get the plugs before the wood is cured, just store them in the refrigerator. You’ll need at least 3,000 plugs per cord of wood; if you want to grow only enough mushrooms for your family, though, 300 or so — about 15 logs’ worth — should suffice. (Of course, the more plugs you buy, the greater the savings. And if you can, buy tapered plugs; they’re much easier to use.)

You’ll also need to gather together a few tools and additional materials: cheese wax (available from cheese-making supply companies; ordinary paraffin is an acceptable, but less desirable, alternative), a double boiler, a cooking thermometer, a hammer, a small paintbrush, a drill and a 5/16-inch bit with a stop collar.

Ready? OK, find a shady area to work in, since direct sunlight can damage the spawn. In each log to be inoculated, bore a row of one-inch-deep holes spaced no more than 10 inches apart; then turn the log about two inches and drill another row of holes parallel to the first but with the cavities offset so that each is alongside the space between holes in the adjacent row. Continue this pattern around the log. (Some growers recommend that woods of light density, such as aspen and birch, be cut to a length of just three feet and the spawn plugs placed every five inches.) Obviously, smaller-diameter logs will take fewer plugs than larger ones.

Once the holes have been bored, it’s important to introduce the spawn immediately; if you drill your logs one day and plug them the next, other organisms will have enough time to contaminate the logs. Hammer the spawn plugs firmly into the holes, flush with the wood, and then use a paintbrush to apply a coating of melted wax over the plugs. (Melt the wax in a double boiler, making sure that its temperature remains under 212 degrees Fahrenheit. Hotter wax will kill the spawn.) Growers in dry, windy climates sometimes also wax one end of each log, to help keep moisture in and contaminants out.

Waiting for the Mushroom Crop

With the inoculation done, restack the logs in a well-drained, shaded area. (At this stage, instead of using the crib stack, many growers lean the logs at a 45 degree angle against each side of a horizontal pole, A-frame style, to provide more growing surface.) The logs will take between one and two years to bear fruit. After your first crop is harvested, however, you can count on additional harvests every spring and fall for the next three to five years. All good things are worth waiting for!

For now, you need only check your logs once a week or so for contamination. If you see surface molds or other fungi, try providing more air circulation around the logs to take care of the problem. If you notice any logs that are heavily contaminated with surface molds, that are losing their bark, or that are producing other kinds of mushrooms, remove them.

Another thing to watch out for is excessive drying. Turning the logs occasionally (twice per growing season is usually enough) helps to keep the logs’ moisture evenly distributed. If you live in an area where the humidity is normally low in the summer months, a porous covering (such as burlap) should be placed over the logs to help them retain moisture. If it’s an extremely dry summer, the logs’ moisture content may be in danger of dropping below 30 percent, the minimum required for the fungus to live. If these conditions occur, test the logs for water content again, and if necessary, soak them. Just a hosing down isn’t enough. They should be soaked steadily with sprinklers or in a tub or nearby stream for 24 hours.

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Shiitake usually fruits in the spring and the fall. You may be able to tell when fruiting is imminent by checking the ends of the log for a white, fuzzy growth called mycelium; if you see it, you know the spawn has permeated the log. If, after 18 or more months from inoculation, you still can’t see any mycelium, cut a thin slice six inches in from the end of a log and place it in a covered jar with a damp cloth. This should force the mycelium to appear within a couple of days.

Once the mycelium shows itself, you can relax a little, because the chances of other organisms contaminating the wood at this point are slim. On the other hand, you may still be in for a wait before the mushrooms appear. Just be patient and trust the power of time and nature. A heavy rainfall — particularly one following a dry period — can cause the permeated logs to begin fruiting. If Mother Nature simply refuses to do the work for you, a good soaking will usually do the trick.

When the mushrooms do begin to form, you’ll need to harvest them daily during the fruiting stage, which usually lasts about a week. Shiitake mushrooms emerge as rounded knobs; as they grow, the brown, gilled caps gradually open and flatten, becoming quite large, approximately two to six inches in diameter. The stems are thick and meaty. The best time to pick a shiitake mushroom is just before the cap flattens completely; simply pull the fungus off the log with a twisting motion. (Shiitake mushrooms are easily distinguishable from most wild mushrooms, but if you have any doubt about the kind growing on your logs, by all means check with someone who can make a positive identification before you consume or distribute them.)

Fresh shiitake stores well for up to two weeks if kept refrigerated in ventilated containers. However, for every hour after the mushrooms are picked and not refrigerated, they lose a day of shelf life — so you’ll probably want to refrigerate them quickly. On the other hand, if you need to store some for longer than just a couple of weeks, or if you want to hold a supply to wait for anticipated higher market prices, they can easily be dried outdoors on a hot, sunny day or in a commercial dehydrator. (Many people say that the shiitake’s flavor is enhanced when dried; to rejuvenate dehydrated mushrooms for cooking, just soak them in hot water for 15 to 30 minutes.)

Mushrooming for Profits

The cost for shiitake spawn averages $30 to $45 per 1,000 plugs. A person who intends to cultivate the mushrooms on a commercial scale (and who would probably qualify for a quantity discount) can expect to spend about $200 on spawn for each cord of wood used.

The return on that cord of wood after fruiting begins should be at least $450 each year for the life of the logs, or about three to five years. This is based on a conservative market-price estimate of $4 per pound, fresh weight. Markets vary locally, of course, so you’ll need to check the going rate in your locale for more accurate earnings projections. Fresh shiitake generally brings the highest prices — but I recently discovered a co-op where dried shiitake was selling for $50 a pound.

As you can see, growing shiitake takes care and patience, but you can successfully cultivate this delectable mushroom and enjoy not only a delightful addition to your dinner table, but an extra income as well. Next time you head out to cut firewood, you just might find yourself eyeing those logs from a different point of view!

Improving Your Woodlot with Shiitake

Researchers at the Forest Resource Center in Lanesboro, Minnesota, where experiments with shiitake cultivation have been going on for several years, see an additional advantage to growing the mushrooms. Joe Deden and Mitch Gilbert, the center’s resident foresters, view shiitake cultivation as an excellent way for landowners to use the small-diameter, low-grade hardwood trees that should be thinned out of a woodlot as a matter of good management. “Families can develop small businesses with shiitake mushrooms that can increase their income and improve their woodlots too, ” Deden says. He recommends that you consult a forester for help !n choosing trees that will both provide suitable shiitake logs and encourage better growth of your woodlot by their removal.

So far, Deden and Gilbert have attempted to grow shiitake on 16 different species of wood, using a variety of techniques. In addition to practicing the traditional Japanese method explained in this article, the foresters have been experimenting with growing the mushroom year-round indoors. They encourage anyone interested in shiitake cultivation to come to the resource center to talk with them and view their operation. “Growing shiitake is a learn-as-you-go proposition, ” says Deden. “We recommend that people start small and then expand their operations as they learn which techniques are best for their areas. “

The Secret Life of a Mushroom

Imagine a thriving vegetable garden in which there are no leaves, no stems, no vines — only vegetables. Some small and rapidly growing vegetables, others plump and fully ripened, still others just emerging — which have slowly come up through the soil from plants beneath the ground.

That, in essence, is what you see when you happen across a patch of mushrooms in a meadow or forest.

A mushroom is only the visible part — the fruit — of a fungus plant. The vegetative portion, called the mycelium, grows underground or (as in the case of shiitake) within an organic host, or substrate, such as wood. Wild mushrooms develop from microscopic seed called spores, while commercial growers usually propagate their mushrooms using spawn: small colonies of mycelia — seedlings, in effect — that have been started in a medium suitable to the species being raised. The spawn, in turn, is then transplanted to the substrate, where the mycelium can spread, mature, and eventually send fruit above ground.

The exact conditions that prompt fruiting are yet to be fully understood, in part because the requirements vary greatly by species (and there are roughly 10,000 mushroom species in North America alone!). Some varieties fruit in response to alternating periods of wet and dry and/or cold and warm, while others require a sustained climate, often one that’s quite humid. Many mushrooms require shade, while others thrive in sunlight (there are several types, in fact, that grow only in desert areas). Some species of mushrooms emerge, ripen, release their spores, and rot within a matter of hours. Yet others — particularly lignicolous varieties such as shiitake — can take years to emerge and, once they do, can grow and develop for weeks or even months before completing their life cycle.

Growing Shiitake Mushrooms: The Most Popular Processes Being Used Today

Do you have interest in growing shiitake mushrooms? Discover some easy ways you can do it

Shiitakes are the second most cultivated mushrooms in the world and the primary mushroom consumed in Asia. Today I’m talking about the processes used for growing shiitake mushrooms.

The first method for growing shiitake mushrooms involves supplemented sawdust. You can get a clear glimpse of this process in the video below.

The supplemented sawdust blocks fruit mushrooms directly from it. In the video you can see fruited bodies that are ready to pick. The shiitakes that are ready to pick have The gills are full and the cap margin is rolled under. I like to say that shiitakes are ready to pick once the cap’s edge curls like a human ear.

The supplemented blocks are created with a mixture of sawdust and wheat bran. In the video you can see the brown of the sawdust. The white is the mycelium of the shiitake mushroom. At the beginning you have a loose block of sawdust. It is then inoculated with shiitake mycelium and about three months later it is ready to fruit. This is the most-common way that shiitakes are grown commercially.

Other terms for this supplemented block growing process may include synthetic logs or shiitake grow kits. When you buy a shiitake grow kit, you receive a mass of sawdust that is held together by the shiitake mycelium. The mushrooms pop out all of the block.

Growing shiitake mushrooms in your backyard

Growing shiitake mushrooms on logs is a great way to do it for yourself at home.

We begin with a natural log. To prepare the log you drill holes in it going all the way up. You then put the mycelium into the log. The log in the video is about three feet long and once it is filled with the shiitake mycelium it is considered to be a full shiitake organism. The mycelium is connected through the entire log and can fruit mushrooms all throughout it.

Log cultivation is best done on hardwood logs like oak, sugar maple, and beech. It is best to select logs that are between 3-8 inches for this method of cultivation. 1 inch deep holes are drilled every 6 inches and shiitake plug spawn is tapped into the holes with a hammer. The log is rotated 2 inches and holes are again drilled every 6 inches. It is best to off set the holes so in the end the drilling makes a diamond pattern. Every hole is filled with shiitake plug spawn and then waxed over. The wax ensures the mycelium will not dry out, and that no other fungi will get into the log. This is the most common answer to the question of how to grow shiitake mushrooms at home.

June through October is the prime time for fruiting shiitakes on natural logs in the northeast.

Shiitake mushroom logs are great for your home garden. It’s simple and you do not need much equipment. The best part is that shiitake logs can help you produce a lot of mushrooms. For instance, if you have 20 logs, that should be enough to supply you with shiitake mushrooms all summer long.

Bonus: You can also try growing shiitake mushrooms on totems

Totems provide a fun and simple way of growing shiitakes. What you do is take a one-foot section of a log and put spawn at the bottom. Then you take another one-foot log section, put spawn between the two, and attached them with some nails. At the top you put another lawyer of spawn and a two-inch disk of wood to cap off the totem. Be sure to also secure that piece with nails as well.

During incubation, after the first two months, we keep a paper bag over the top so the mycelium has a chance to grow over the logs. We allow the totems to stay in place and rest; we do not shock them with water, but they do get wet when it rains naturally.

Totem growing is the quickest method to try outside. You don’t have to drill as many holes or close them up as you would with the log cultivation. It is another popular method for growing shiitake mushrooms that is often done outside. However, you could also use totems indoors if you are growing commercially and have the space.

If you are growing mushrooms indoors but not doing it commercially and want another method you can try our mushroom growing kit. If you want to go beyond shiitakes, try out any of the mushroom growing kits we offer, which include oyster mushrooms, lion’s mane mushrooms, chestnut mushrooms, and more.

Want to start growing your own shiitakes at home? Check out our shiitake mushrooms plug spawn for log inoculation; Our supplemented sawdust shiitake spawn for a variety of growing; And our shiitake mushroom grow kits.

Difficulty: Beginner/Intermediate

Shiitake mushroom kits are one of the easiest of all of our Grow Your Own kits. They are very reliable producers as long as the ambient humidity in their growing environment remains consistent. Because the block is removed entirely from the bag, they are prone to drying out. Using a humidity tent will help mitigate this issue as long as there are enough holes in it for proper gas exchange.

Cooking: Shiitake mushrooms are widely used in East Asia and lend themselves to the aromatic and bold flavors of Chinese and Japanese cuisine. Try pairing them with soy sauce, mirin (sweet rice cooking wine), ginger, and garlic. We love to marinate shiitake with these ingredients and then skewer them for the grill. Serve them with sticky white rice and hit with a dash of rice vinegar. Dehydrated Shiitake possesses an almost ethereal savory aroma that can be used to booster soup stock with powerful umami.

Properties: In addition to acting as a general immune system booster, Shiitake can be used as a tonic to promote overall liver and kidney health (Marley, 2009). Shiitake also contains high concentrations of the substance eritadenine, which may be beneficial in reducing blood cholesterol levels (Enman et al., 2007). Beyond helping relieve an ailment, Shiitake has nutritional value due to its ability to absorb Vitamin D. Drying Shiitake in the sunlight will increase Vitamin D levels by more than a hundred times compared to Shiitake dried in the dark (Stamets, 2005).

Directions

1) Your Shiitake mushroom grow kit is an amended sawdust block that has been completely colonized by Shiitake mushroom mycelium. WAIT TO START YOUR BLOCK UNTIL IT HAS TURNED BROWN. Take the block and put in the refrigerator overnight. Remove from fridge and entirely remove and discard the plastic bag covering the block, exposing the raw block of colonized sawdust.

2) Soak your block in cold water for 4 hours.

3) Mushrooms need proper humidity and ventilation to survive. Place your block on a plate in the most humid part of your home and outside of direct sunlight. We suggest putting your block on a kitchen counter somewhat close to a sink. In the winter months, and if your home is really dry you may want to make a humidity tent to place over your block. Simply take a trash bag or other loosely fitting plastic bag and put PLENTY of 1/2 inch holes in it (THIS IS IMPORTANT: Mushrooms exhale CO2 and inhale oxygen. They will suffocate themselves if there isn’t adequate airflow! Shiitakes that look strange or have unusually fat stems are usually growing that way because they need more air!). Spray the outside of your block least once per day until the mushroom block forms baby mushrooms (called ‘pins’). If you choose to use a humidity tent make sure to spray the inside of the tent once per day to maintain humidity.

4) Harvest your mushrooms when they resemble the photograph on the front of your kit! Harvest before the caps flatten out and become soft or soggy. Mushrooms grow quickly, so when you spot your first mushroom pins keep a close eye on them. The warmer the environment the faster they will grow. Mushrooms should be ready to harvest 4-10 days after pin formation.

5) We guarantee the first harvest of Shiitake mushrooms, but you may choose to attempt a second fruiting off your block! Harvests usually diminish in size with each consecutive fruiting. We recommend giving your block a one week break from spraying, then soaking your block in cold water for 20 minutes and re-starting the process of spraying your block with water daily!

*CAUTIONS AND CONSIDERATIONS:

IF YOU PLAN ON CONSUMING YOUR HOME-GROWN MUSHROOMS MAKE SURE TO COOK THEM THOROUGHLY. IF IT IS YOUR FIRST TIME EATING THIS SPECIES, IT IS BEST TO START WITH A SMALL AMOUNT TO SEE HOW YOUR BODY RESPONDS!

MUSHROOMS PRODUCE SPORES AS THEY DEVELOP. THIS IS A NATURAL MEANS OF REPRODUCTION FOR THE FUNGUS. THEY USUALLY APPEAR AS A DUSTY SURFACE ON YOUR GROW KIT BENEATH THE MUSHROOM CAPS. PEOPLE WITH ALLERGIES OR COMPROMISED IMMUNE SYSTEMS MAY WANT TO CONSIDER PUTTING FRUITING MUSHROOM KITS OUTDOORS OR IN A WELL-VENTILATED AREA AS AIRBORNE SPORES SOMETIMES CAUSE RESPIRATORY IRRITATION. SPORES MAY ALSO CAUSE IRRITATION FOR SOME NON-ALLERGIC OR IMMUNE COMPROMISED MUSHROOM GROWERS, THOUGH THIS IS RARE. HARVESTING MUSHROOMS WHILE STILL IN THEIR YOUNGER GROWTH STAGES WILL REDUCE THE OVERALL SPORE LOAD.

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