The Fuss about Fungi

As a newbie garden writer, I didn’t foresee writing about soil microbiology.  I thought I’d write about the magic that is gardening.  I envisioned sweet prose on the joy of watching delicate petals reveal themselves and reach for the sun. I wanted to share the pleasure of watching late-evening light dance on a colorful leaf.

But nope.  I’m blathering about dirt.  This is actually more useful.

Soil IS magical. And even if it means typing mycorrhizal fungi twelve times, I must share some of what I learned Saturday from Dr. Roger Tai Koide, Professor of Horticulture Ecology, Penn State University during the Manada Conservancy’s Native Plant Sale held at Meadowood Nursery.

Dr. Koide is enthralled by fungi.  I know.  How could he NOT be?  But his passion for the topic made soil biology as interesting as “Jersey Shore.”

There’s so much to know about fungi. I learned bunches from his talk, but a few gems really got me thinking. Here they are; Cover crops aid beneficial fungi in the soil and commercial mycorrhizal fungi products have questionable value.  Koide also said to pamper the fungi in your soil with mulch and by leaving soil undisturbed as much as possible.

Mychorrhizal fungi are more numerous in soil that has actively growing plants in it.  Plants grow better because of the added root structure and added ability to take up nutrients, when mycorrhizal fungi are living on – and in -the plant roots. Mycorrhizal fungi need plant roots to thrive because of the symbiotic relationship they have with plants. I wrote about that in my Earth Day post.

All this leads to another reason to use cover cropping.  In order to keep fungi numerous in your soil, to benefit your plants, you need to continually offer fungi a place to live,  ie… plant roots.  Fallow times or areas in your garden or between crops, reduce numbers of mycorrhizal fungi in your soil.  Doesn’t that make perfect sense?  But you need to make sure the cover crop is a mycorrhizal plant.   Some plants aren’t host to mycorrhizal fungi.  Interestingly, a popular cover crop, buckwheat, isn’t a host.

Dr. Koide said that if densely planting or using a cover crop seems like too much for you, consider mulching gardens in between plantings to protect the Mychorrhizal fungi from the freeze and thaw cycles. He also suggested limiting soil disturbances like tilling or double digging to protect the fungi.

Another fascinating thing he shared was about commercially available products that claim to add mycorrhizal fungi to your soil.  He wasn’t convinced they work very well.  I’d heard suspicion about that before.

This Maine farm will grow a cover crop rather than leave the soil fallow.

On that topic too, even if it is possible to large scale package and sell live fungi, he pondered the wisdom of transporting mycorrhizal fungi from area, where it natural and native to another area where it would be foreign to the soil.  Sounds like trouble to me.

A good way to add mycorrhizal fungi to new topsoil is to inoculate it with existing soil from your garden, he said.  Just shovel some existing soil onto your beds.  The fungi have the ability to find plant roots and travel through your soil.

Given everything Dr. Koide explained, by the end of his talk, I had concluded that conventionally farmed land would be virtually free of fungi because of the use of chemicals and yearly tilling.  He said that most agricultural chemicals don’t harm mycorrhizal fungi.   Surprising.

If you get a chance to hear Dr. Koide, I’d recommend it.  He certainly got my brain engaged.