The requirements to grow mushrooms are relatively simple. They need the proper temperatures to carry out various stages of growth, which is achieved simply by planting them at the right time. Mushroom inoculation (planting) can be done from March to October (whenever there aren’t regularly freezing temperatures). However, as they can struggle to thrive during the heat and dry of summer, they are best done in the spring or early autumn. Late autumn will not allow for proper establishment before winter dormancy.
Mushrooms need consistent moisture. This is imperative. If you can’t maintain adequate moisture levels, any other work will simply have been wasted.
Conveniently, mushrooms are shade tolerant. Though they don’t require it (in fact, most mushrooms do like some environmental light), this tolerance means they can occupy spaces where solar-powered plant life will not grow, and shade will help to maintain the moisture and high-humidity levels they want. However, their mycelium (the initial and underground growth of the mushroom) can’t be constantly wet, so they require adequate drainage.
The substrate, or growing media, each mushroom species prefers is an important distinction amongst them and perhaps how their production differs most from garden plants and one another. They may require straw, compost or wood chips (properly aged and not from an aromatic softwood) to provide the nutrients they want.
Areas are prepared for inoculation by digging a bed and laying down the proper substrate, which is presoaked for a head start on maintaining adequate moisture levels. The inoculant or spawn is then spread. Or, alternatively, thinner layers of substrate-inoculant-substrate-inoculant are used.
The completed bed is then covered with 2 to 4 inches of loose mulch (also called casing), typically of straw or chopped leaves. The casing helps maintain moisture levels and, when thickened for overwintering, protects against cold weather.
Mycelial growth uses the substrate (i.e., food source) you have provided until it’s exhausted and the area is colonized. This triggers the next stage of growth, which is the sexual reproduction of spores via the fruiting body of the organism—in other words, the mushroom. Complete colonization is very species- and growing-conditions dependent and could take from 6 to 9 months, or to 12 or perhaps longer.
Garden-friendly mushroom species are listed in this article. Within each species you can find specific strains that possess preferences in temperatures, planting times, light levels and/or substrates. Pay attention to these variations when selecting your inoculant.
Almond Agaricus (Agaricus subrufescens)
Closely related to the button mushroom, the Almond Agaricus boasts a similar shape with an off-white color. With a somewhat sweet taste and an almond scent, this mushroom fruits throughout a generous range of temperatures (50 to 95 degrees F).
Wine Cap (Stropharia rugoso annulata)
Also called king stropharia or garden giant or even Godzilla mushroom, this highly attractive species produces large, port wine caps (of 7- to 12-inch diameters) atop ample white stipes (stalks). An aggressive grower in sun and shade, the wine cap has a slightly nutty flavor.
Oyster (Pleurotus spp.)
Oysters are very aggressive and fast-growing. There are many species, which sport fluted or shelf caps and are grey, yellow, pink or various off-white shades in color.
Elm Oyster (Hypsizygus ulmarius)
With a firmer texture and richer flavor than the true oyster mushrooms it resembles, the elm oyster is larger and of a cream-to-white color.
Wood Blewit (Lepista nuda, also known as Clitocybe nuda)
The wood blewit possesses a sweet scent and an earthy, slightly yeasty flavor. It also has a sturdy stem and bluish-lilac cap.
Bleu Foot (Clitocybe sordida)
Compared to the wood blewit, bleu foot has a milder flavor (somewhat sweet and earthy), an earlier fruiting date (due to its preference for warmer weather) and a darker cap, which is wildly wavy.
Shaggy Mane (Coprinus comatus)
This mushroom produces a bell-shaped cap with a flakey surface. It does well in exposed, grassy areas and is primarily an autumn fruiter.
Meeting Mushroom Needs
Mushrooms need to be planted on a substrate that will support their growth. While some species of mushrooms grow on very limited materials, others grow on more varied ones. Almond agaricus, bleu foot and shaggy mane grow best in compost. While wine cap mushrooms grow happily in straw and wood chips, the true oysters and elm oyster prefer straw and various organic waste materials (yard waste, coffee grounds, etc.). However, blewits can survive on compost, wood chips or waste materials.
Substrates that break down rapidly—such as straw and compost—offer a quicker mushroom harves. However, the bed as a whole will remain productive for a shorter time. Therefore, bleu foot tends to bring a very rapid late summer or autumn harvest from a spring planting (on a potentially short-lived bed), while wine cap plantings on wood chips take longer to fruit but yield repeated harvests readily.
Naturally, wine caps grown on straw yield a harvest more rapidly than when grown on wood chips. For species that can grow on many substrates, a mixture will often offer the best results.
Several components affect the speed with which mushroom colonization takes place, some of which are related to substrates and bed assembly. The larger the area you want to inoculate, the more spawn you will need for the process, or the longer it will take if you go light (“area” referring to both surface area and depth).
Thus, a 5- to 7-inch-deep bed will take longer to colonize than a shallower one but will produce larger mushrooms when it does and for longer.
The age of your substrate (i.e., state of its decomposition), its particle size (large or well chopped pieces of wood, straw, leaves, etc.) and its exact composition due to its parent species will all impact the process as well. And the season of planting, not to mention the exact temperature and moisture conditions, have their impact, too.
A wonderful aspect of mushroom production is its perpetual nature. Mushrooms will continue to grow in their established locations until they have exhausted all available substrate. Fresh substrate and mulch can be added after harvesting is done for the year to support new growth the following season.
Also, substrate colonized with mycelia (easily identified by its white appearance) can be taken from established beds and used to inoculate new areas. Properly managed, mushrooms will pop up for years!
It’s ideal to start mushrooms in areas free of perennial weed pressure. The best locations to establish your mushrooms are, quite naturally, dependent on the species and the arrangement in which you are going to place them. Those mushrooms that grow on substrate that also makes plants happy (such as compost) can more easily be grown within the same space. This would be the almond agaricus, shaggy mane, bleu foot and wood blewit.
For mushrooms that grow on wood chips and straw, some soil must be included while preparing beds for the plants’ initial growth, which is done for the oysters, elm oyster and wine cap. Alternatively, beds built solely for mushrooms can be prepared bordering vegetable rows. Mushroom mounds of this fashion are typically a foot wide.
Disturbance of mushroom mycelium means wasted growth (mycelium will have to reestablish itself wherever it is grown and destroyed, requiring the necessary resources be used twice) and lost time. Therefore, you must arrange your mushroom and produce crop planting accordingly.
Mushrooms may be planted around bed perimeters in the autumn, leaving a center space for produce planting in the spring. Following autumn-planted mushrooms with a crop in the spring often means you will harvest both that year. Crops planted in the early spring may be placed out at the same time as your mushroom inoculant, allowing simultaneous initial growth.
Some plants are better suited to fostering mushroom production than others. Plants that grow large, have large leaves and/or display a bushy growth habit later in the season when shading are ideal. Options include:
- nightshades such as tomatoes, eggplants, garden huckleberries, cape gooseberries and your bushier pepper plants
- brassica crops such as Brussels sprouts and broccoli (which are extremely responsive to the growth benefits described later)
- some cucurbits—cucumbers, zucchini and summer and winter squash, bearing in mind that bush-type plants will allow better access to mushrooms than the extremely large, vining plants.
Other crops include straw-mulched corn (which partners well with wine caps), and pole beans or any other trellised or “teepeed” crops. Additionally, wine caps kill root nematodes, small worms in the soil which frequently damage crops. Growing them concurrently or rotationally with susceptible crops (including beets, carrots, tomatoes, peppers, cucumbers, squash and radishes) would be highly beneficial.
You should consider that integrating mushrooms into a crop you already mulch will save you from having to acquire more mulch materials beyond what you normally use, which is worth considering if your resources are limited. Also note that as an added insurance, growers sometimes do initial inoculations only on the north side of the plants, as they’ll better maintain the desired humidity levels and cooler temperatures on their shadier sides.
Finally, well-mulched and maintained perennial areas are another spot for mushrooms to grow. For example, asparagus and rhubarb beds, grape rows/arbors, perennial garden flower and herb beds and caning fruit rows are ideal.
More Than Mushrooms
The cultivation of mushrooms provides benefits beyond their value as a food source or additional revenue should you sell some harvests.
Fungi attain their nutrition by breaking down organic materials and are particularly valuable in the decomposition of cellulose and lignin, compounds that are especially persistent in woody debris. By unlocking nutrients from these materials and releasing them into the soil, their role as nutrient cyclers is invaluable and stimulates an increase in garden produce size, yield and nutrition.
Elm oyster and wine cap are extremely efficient in this role. Mushroom activity also decreases the need for additional garden fertilization. The mycelium of fungi improve soil tilth and aeration while enhancing its water holding capacity and thus increasing moisture availability for plants.
Collectively, this means improved soil structure.
Mushrooms grown within produce beds will function as weed suppressors, especially those that are larger and aggressive. Alternatively, a bed containing mushrooms may be used exclusively for vegetable production the following year, for which it will have produced a wonderfully conditioned soil.
Some practitioners of mushroom/produce intercropping and successional planting feel that with the excellent crop growth and soil benefits provided, the actual harvesting of mushrooms could be regarded as purely a bonus—a wonderful, edible, tasty bonus!
You can grow many of the following mushrooms in a diversity of homestead locations.
Shaggy mane and especially the highly decorative wine cap can be successfully grown in landscaped beds that have low-lying shrubs.
They’re all about microorganisms breaking down waste materials into nutritive compost. Let the bleu foot and wood blewit have charge of your piles!
Greenhouses & High Tunnels
Almond agaricus, bleu foot and wine caps do very well underneath trellised tomatoes, cucumbers or other plants in covered production.
For those who enjoy bale gardening, raising oyster mushrooms on them should feel natural.
Produce mushrooms on logs in the garden! Settle inoculated logs along your production bed perimeters or garden pathways—practical, productive and decorative. Place them on sand and cover with mulch for protection through the winter.
Certain strains of oyster are ideal for wood-based production. This is also your opportunity to try portobellos and shiitakes.
Pots for Logs
Short on space? Place your inoculated log (upright) in a flowerpot and start watering. Again, oyster, portobello and shiitake.
Plant Guilds (Orchards)
A guild is a grouping of mutually beneficial species, constructed to create an ecosystem-type setting that enhances the productivity of each member. They typically include trees, shrubs, vines and understory plants, and can easily incorporate oyster, shaggy mane and wine cap mushrooms as well.
If well-drained and weed free, the understory of trees (with dappled sunlight) provides an excellent mushroom area. You could grow elm oyster, oyster or wine cap, or even portobello or shiitake on any logs or tree stumps that need to be dealt with as part of your woodland management.
Hedgerows & Sheltered Fields
Again, if these areas are well drained, weed-free and have a protected soil surface (i.e., naturally occurring plant debris), you can introduce elm oyster, oyster or wine cap into the landscape.
Underneath Black Walnuts?
As anyone with black walnut trees knows, they produce a substance called juglone that prevents other plants from growing near them. However, mushrooms aren’t deterred as it doesn’t affect them. Furthermore, wine caps can neutralize the chemical, offering some protection to susceptible plants close by.
This article originally appeared in the May/June 2023 issue of Hobby Farms magazine.