A fungus among us

Compost and mulch, compost and mulch, I had heard it a million times. But Lowenfels and Lewis’s book was an eye-opener. Certain of our edible plants prefer soils which are heavily populated by bacterial soil life. Others of our edible plants prefer to grow in fungally dominated soils. What is more, we can make all this happen – low cost/low inputs – by what we do as gardeners.

Wow.

It turns out that our annual veggie beds want bacterially dominated soils. Our fruit tree orchards and our perennial plants want fungally dominated soils. Fungally dominated soils apparently have plenty of bacteria too, but they just have more of the mycorrhizal fungus.

These discoveries explain why one can never have both a great lawn and a healthy tree in the same spot. You’re either catering to one or to the other but you cannot please both.

Lowenfels and Lewis go to great lengths to describe how to tweak your compost production to make it more bacterially dominated or not. But realize that either classification of plant gets its bacterial dose from the compost. The real differences are in the mulch.

Mulch for annual veggies: grass clippings (no seed heads), straw (not hay). Wet, small particles. (Cultivates bacterial populations)

Mulch for perennials and fruit trees: autumn leaves, wood chips. (Cultivates fungal populations. Also more acidic.). Mulch from trunk to dripline. Eliminate lawn beneath trees.

Within organic gardening circles you will often hear people mention the need for mycorrhizal fungus. Lowenfels and Lewis help us to understand that the different types of plant crave different species of mycorrhizae.

• For most veggies you’re seeking ENDOmycorrhizal fungi.
• ECTOmycorrhizae is for pine and fir and hardwoods.
• Brassica family (cabbage, broccoli, mustards, etc) and Chenopodiaceae family (chard, beets) do not form relationship with mycorrhizae

It is a waste of money to be buying the wrong kind of mycorrhizae for your plant, and a waste of money to be buying broad spectrum combinations.

These subtle differences will become important in Chapter 5 when we discuss perennial edibles, and in Chapter 4 when we cover vegetable crop rotations.

Next: Soil Critter Care Sheet