I repost something that Anton posted here back in 2000:

Subject: Is mycorrhiza important?
Date: Friday, June 02, 2000 10:30 AM

There is a mycorrhiza list that is run out of the University of
Guelph and there is a fair amount of research going on around
the world. I have been lurking for several years and so far the
info that I have compiled in a nutshell is:

There are thousands upon thousands of varieties of myc. and then
some. The sale of myc. unless it is registered is not legal in
most areas. (this came from an EPA lawyer). There is a 99.9%
chance the myc. that is commercially available is not compatible
with the plant that you intend to apply it to.

Phosphorous in the soil reduces myc.

Myc. produces carbon traps in the soil.If you use native plants
to your area chances are your plant will inherit it anyways.
Myc. is most beneficial under adverse growing conditions.

.. . . . I do not think that because it is beneficial to a forest
under certain conditions that you can draw the same correlation
to a bonsai container. To prove any of this is almost
impossible.

Anton Nijhuis
Vancouver Island

I've seen nothing in the intervening years that refutes this
information.

That said, the Roots product MAY contain the myc. that go with
specific pines and junipers that are often used for bonsai;
someone gave me a couple of bottles of Roots Plus (which is NOT
the myc. mixture!) and, as usual in these kinds of concoctions,
the labels are uninformative.

Jim Lewis - - Tallahassee, FL - Nature
encourages no looseness, pardons no errors. Ralph Waldo Emerson

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