jko at xprt.net
Tue Jul 4 05:35:18 EST 2000
This FAQ tries to connect agroforestry and gardening
through fungi. Comments and corrections are welcome.
Garden Fungi FAQ
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 of 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 a fungi
which activate when the needle is attacked. This in
essence is the immune system and adapts in areas where the
tree is unable to adapt.
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 mycologist at present but the supporting
evidence is growing.
Some interesting facts about soils and fungi:
* Of the estimated 6 million species of fungi we have
cataloged 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 part of one of our biggest
frontier 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. Also, some
non fungal pests can be controlled by fungi, so usually we
end up gaining more than we lose.
Can i buy fungi and add them to the garden?
Yes, many people add sprays which contain fungi. Often,
these are mycorrhizal fungi which form relationships with
plants. The brewing of compost teas is another way to
improve the fungi balance. One major consideration is
fungi habitat. If we fail to build good habitat then it
may be necessary to buy replacement fungi each year, not a
very sustainable approach and possibly expensive.
What is ideal fungi habitat?
It is doubtful that all the fungi in the world will be
known or all the roles they play. This makes precise
answers difficult but we can make some generalities.
Fungal dominated soils occur in forests and grass lands
with the following characteristics:
1. Stable perennial plant cover to interact with.
2. Mulch layer as food supply. (For prairies it
is reversed, root death provides the food)
3. Mostly undisturbed soil (not tilled)
Another characteristic is diversity and change. It is
common for a fungi to find a home and spread slowly
consuming its preferred food and leaving a open center.
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?
Observation is the best method. Soil tests do not work
very well when dealing with living tissue and diversity.
Some of the clues come from plants and others come from
looking at the soil. The smell, feel, and moisture
retaining properties are all clues. Weeds are probably the
best indicator of all. If we can identify the weeds and
know what environment they prefer we can predict how
similar crops will perform.
Some plants who prefer fungal soils are: conifers, grape,
apple, forest plants, most deciduous trees, citrus,
So how do i use all this information?
Increasing soil bioactivity and being aware of how balance
works is a good place to start. Another is to look at all
the techniques which 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 eco system.
Several books exist on this topic.
The study of agroforestry includes other systems with
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 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.
What about pesticides and herbicides?
Caution to the point of complete avoidance is the safest
approach with pesticides. Some of the natural compounds
are useful, but where possible building healthy eco systems
with predators is much preferred. Often this is more labor
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?
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. Then spread a woody
material on top. 2. buy mushroom kit and grow the
mushrooms, then spread the spent spore and cover. 3. buy
mushroom spore or plugs and inoculate the garden directly.
For most gardeners the first method is most reliable.
Another method is to obtain a known mushroom 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 (see THE FARM web
pages for techniques).
Which mushrooms are recommended?
Gardeners should first decide it 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
Shiitake, can be grown on wood
Shaggy Manes, can be grown in manured soils and near
The Mycorrhizal species (chanterelles, king boletes,
matsutake, and truffles) are possible candidates for
seeding by slurries or inoculated trees. This seems to be
a controversial issue still. A few people claim success
and others are questioning the results.
A good source of 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.
Gourmet Mushroom Products
Mushroompeople (The Farm)
Compost tea FAQ
Don Chapmans inoculants
Other Fungi Information
Canadian site for agroforestry
Agroforestry site with newsletter
The Farm, Summertown, Tennessee intentional community
Growing Gourmet and Medicinal Mushrooms
by: Paul Stamets
The Hidden Forest
by: Jon R Luoma
(Special thanks to Guy Clark for translating
the following book into eco-speak)
The Nature and Properties of Soils
Nyle C. Brady
This FAQ probably has errors and would benifit from
additional information in some areas. If you see potential
improvement please help others and yourself by sending comments
to jeff owens at:
Email: jko at xprt.net
Web Page: http://www.xprt.net/~jko
or to the ecopath discussion list at ecopath at csf.colorado.edu
This FAQ can be found at:
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