Why should I be interested in fungi?

Building good soil begins with fungal activity and many diseases are both caused and solved by fungi. Some plants are so dependent on fungi that they can’t survive without them. This relationship can be at the root zone or in the leaves. It is now known that some fir trees have fungi that activate when the needle is attacked. This in essence is the immune system and adapts in areas where the tree is unable to adapt. Fungi should be encouraged where the soil is cultivated using vegan organic methods.

It is also suspected that the decline in forest and farm soils is related to fungi diversity loss. This view seems to be mainly among mycologists at present but the supporting evidence is growing.

Some interesting facts about soils and fungi:

– Of the estimated six million species of fungi we have catalogued about 50,000.

– An important component of soils are actinomycetes, which have been called both fungi and bacteria.

– Fungi can selectively modify soil pH.

– Fungal die-off is an early sign of ecological collapse.

All this indicates fungi as part of one of our biggest frontiers to be explored: soil.

If we encourage fungi won’t that also encourage fungal diseases?

It is usually a question of balance. The fungi are always around and we want to make sure their predators are also around. Often those predators are other fungi. In addition, fungi can control some non-fungal pests, so usually we end up gaining more than we lose.

Can I add fungi to the soil?

Yes, the brewing of compost teas is one way to improve the fungal balance. These can be made by steeping a cloth bag of mature compost in a barrel of water, or cramming nettles/comfrey/weeds into a barrel of water. In each case, leave for a few weeks, then dilute with about three times as much water and spray on bare soil or around plants; a little molasses can be added to the brew. Preferably use rain or well water as the chlorine in tap water inhibits fungal growth. Such brews are smelly but high in soluble nutrients and will feed plants and the soil; see our article on making your own plant feed.

What is ideal fungi habitat?

It is doubtful that all the fungi in the world and the roles they play will ever be known. This makes precise answers difficult but we can make some generalisations. Fungal-dominated soils occur in forests and grasslands with the following characteristics:

1) Stable perennial plant cover with which to interact.

2) Mulch layer as food supply. For prairies it is reversed, root death provides the food.

3) Mostly undisturbed soil (not tilled).

Good habitat for fungi: crop diversity, mulch, permanent cover, no till. Photo: Stephane Groleau

Other characteristics are diversity and change. It is common for a fungus to find a home and spread slowly, consuming its preferred food and leaving an open centre. This appears as a ring of mushrooms after a few years. It is called a fairy ring and may not seem interesting, but consider this: a fairy ring 150 miles across was discovered in the American midlands. This suggests slow change everywhere these rings are growing and interacting.

The diversity factor consists of fungi populations eating each other, being eaten by just about everyone, and constantly changing. It is impossible to predict all the soil interactions so one answer is diversity. Have the good guys present and ready to fill the niche.

How do I know if my soil has a good fungal balance?

Once the land has been cultivated using vegan organic methods for some years it is likely to be in good shape, assuming that proper techniques have been used. If the land has been fallowed, treated with fungicides (especially those used to control club root), intensively cropped using chemical fertilizers or overdressed with animal manures (which can contain powerful fungicide residues or cause over-acidity) then it would benefit from the use of compost teas or other additions of fungus. Various adverse soil conditions such as over-liming, alkalinity, waterlogging or lack of humus will inhibit a good fungal balance.

The performance of vegetation is often a good indicator. If plants are growing poorly then there can of course be many reasons – refer to a good handbook on growing fruit and veg, but additions of fungus can also be made. Some plants that prefer fungal soils are: conifers, grape, apple, forest plants, most deciduous trees, citrus and strawberries.

So how do I use all this information?

Increasing soil bioactivity and being aware of how balance works is a good place to start. Also look at all the techniques that use perennials mixed with annuals to build habitat. This includes:

– Alley cropping: nitrogen-fixing trees coppiced to provide mulch. Mixing alders and potatoes, for example. This appears to provide sustainable yield. The alders work in conjunction with actinomycates at their roots.

– Forest Gardens: this technique mixes perennials with annuals and attempts to build a diverse ecosystem. Several books exist on this topic.

– The study of agroforestry includes other systems with similar characteristics.

Other things to consider are no-till and limited crop rotation. Where soils need to be tilled the use of compost teas can help restore the soil life balance. Teas can be brewed for increased bacteria by increasing the sugars or for increased fungi by increasing the cellulose, starch, and gums. Year-round gardening is another good technique. Having plants around also helps their supporting fungi to survive. If we combine this with mulching and a few perennials our diversity is maintained and the soil is much more adaptive.

Even land in good condition can benefit from a maintenance application of compost tea if you have the time and opportunity to do it.

What about pesticides and herbicides?

Caution to the point of complete avoidance is the safest approach with pesticides. Where ever possible building healthy ecosystems with predators is much preferred. Often this is more labour-intensive and can impact profits. On the other hand, it provides meaningful work and connects us back to the land.

Can I grow edible mushrooms in my garden or allotment?

Shiitake mushrooms growing on a log. Photo: Gourmet Woodland Mushrooms

Yes, but reliable results are difficult without careful procedures. There are also problems with identifying mushrooms, which need to be considered. We are surrounded by fungal spore looking for a home and this presents some problems. In commercial mushroom farms about half the work is maintaining spore and propagating it. This spore is then used to quickly inhabit a sterile medium. Even these commercial methods sometimes fail.

Some things gardeners can do are: 1) Buy a mushroom kit and spread the inoculated medium on a suitable shady patch of rich soil or lawn; then spread a woody material on top, 2) Buy a mushroom kit and grow the mushrooms, then spread and cover the spent medium in the same way, 3) Buy mushroom spore or plugs and inoculate the garden directly, again selecting a shady patch of rich soil or lawn. Choose a damp day in spring or autumn to attempt these methods. We don’t know if these products will be vegan organic at source, animal manure is often used in commercial mushroom production.

Another method is to obtain a known mushroom spore from the store or other source. This can be mixed with a dilute molasses slurry and left to grow. The result can be sprayed in a good habitat and may take up residence.

Which mushrooms are recommended for garden growing?

Gardeners should first decide if they have a site suitable for mushrooms and then pick types that will fit the habitat. Here are some candidates:

– Oyster, one of the easier mushrooms to grow but it can be confused with other mushrooms. Habitat would be compost piles or a prepared medium.

– King Stropharia, can be grown in soils amended with chopped straw.

– Shiitake, can be grown on wood.

– Shaggy Manes, can be grown in very rich soils and near compost piles.

– The Mycorrhizal species (chanterelles, king boletes, matsutake, and truffles) are possible candidates for seeding by slurries or inoculated trees. This still seems to be a controversial issue. A few people claim success and others are questioning the results.

Information on mushroom gardening can be obtained from Paul Stamets’ books and from local mycological societies. Trial and error procedures can be risky with mushrooms so good information is important.

What about collecting wild fungi from the garden or field?

Many people collect wild fungi to eat, but the greatest caution must be observed. Most of the common edible types have nasty or deadly look-alikes; you can pick up toxins just licking your fingers after handling some species. Overpicking may deplete a species. The illustrations in many guides can be deceiving. Unless you are really an expert, don’t take risks, and don’t believe your friends either, who may think they know what’s edible.

Mushroom Sources

Gourmet Woodland Mushrooms www.gourmetmushrooms.co.uk. One of the aims of this vegan-run company is to promote the cultivation and consumption of wood decomposing mushrooms as an ethical, healthy and tasty alternative to the ubiquitous button mushroom. They run introductory training courses to familiarise potential cultivators with the techniques required to produce commercial crops from low grade timber and associated by-products. They offer a 50% discount on courses to charitable institutions and their members. They also sell DIY oyster and shiitake kits, which can be grown out of books or wood.

Fungi Perfecti www.fungi.com

Mushroom Adventures www.mushroomadventures.com

Other Fungi Information

MycoWeb www.mykoweb.com/links.html

Books

Growing Gourmet and Medicinal Mushrooms by Paul Stamets (US)

The Hidden Forest by Jon R Luoma (US)

Forest Gardening by Robert Hart (UK)

This article was originally VON information sheet Num 5. Last update: 2016