The mushrooms that bloom in the rain

We've had a little rain in Chicago this year. In the last 90 days more than 17 inches of precipitation, 148 percent of normal, has fallen on northeastern Illinois, according to the Illinois State Climatologist's Office. That leads to all sorts of unpleasantness--flooding, leaky basements, mosquitoes, West Nile virus, bad rush hours, twice-a-week lawn mowing--but it gives us at least one good thing: mushrooms.



When I was a garden writer for the Chicago Tribune, heavy rains often brought phone calls and emails from readers complaining "I have all these mushrooms!" My usual response was "Congratulations! That means you probably have great soil!" Then I would try to convince people who were anywhere from repelled to terrified that the proper response was respect and tolerance, if not pride. In any case, not herbicides.

Mushrooms, after all, are merely the fruiting bodies of underground fungi, those empires of slender filaments that spread under the soil. They feed on plant matter, releasing its nutrients so they can be used by plants and other organisms. When the fungi are well-fed and they get the right amount of moisture they send up mushrooms to make more fungi.

If you have mushrooms in your lawn or garden, it's a sign that your soil has lots of decaying plant matter to be chewed over by all the members of the underground ecosystem that keeps plants happy. If a concentration of mushrooms keeps popping up in one area, it may be the spot where a tree was cut down but there is still a woody root system to be disposed of, supporting plenty of fungi.

When triggered by rain, those fungi propagate themselves by producing spores--not seeds, but something similar, the microscopic germ of life that can become another fungus. And spores are often delivered by mushrooms.

The typical mushroom, as my friend Greg Mueller once explained to me, is an elevator. Its purpose is to raise the spores high enough so that when released they can be caught and wafted away by the wind. It doesn't have to rise very high--spores are so tiny and light that just an inch of elevation may be enough to let them ride a breeze from beneath the mushroom's cap.

Some mushrooms are instead structured to distribute spores in rainwater. Other fungus fruiting bodies, which we don't call mushrooms because they don't have that iconic shape, cling to the sides of trees or logs that the fungi are digesting. Then there are puffballs, globes with spores inside, which dry out and wait for an animal (perhaps a human one) to step on them and distribute the spores in a dust cloud.

And for every spore, we should be grateful. Fungi form beneficial relationships with the roots of trees and break down vast quantities of plant matter. Without them, civilization would be buried in unrotted trees and lumber and mountains of leaves, every leaf that ever fell.

Though many people assume that all wild mushrooms are poisonous, most are not. I enjoy spotting mushrooms in my yard; I'm quite vain of them. I know they mean I've made the fungi underlying my lawn happy with plenty of compost and other organic matter and I haven't damaged them with pesticides or too much fertilizer. I like wondering how far the threads of my mushrooms' parent fungi extend under the soil--to the next block? to the railroad tracks? Fungi have been found that are thousands of years old and stretch for miles. I enjoy thinking about all the legends and mystery that the sudden, fleeting appearance of mushrooms (and the psychotropic properties of some) have provoked over thousands of years.

Greg was curator of fungi at the Field Museum in Chicago (which has a great exhibit for kids about all the things, including fungi, that live under the soil) and has studied mushrooms all over the world. Now he is vice president of science and academic programs at the Chicago Botanic Garden in Glencoe. He is an ace mushroom hunter and mushroom epicure.

Hence the fun book he has written with Joe McFarland, "Edible Wild Mushrooms of Illinois & Surrounding States: A Field-to-Kitchen Guide." (Here's the companion web site.) From the book, you can learn to tell the difference between the poisonous Jack O'Lantern and the delicious Yellow Chanterelle. You can learn when and where to look for morels and how to use household cleaning products to make sure you've picked a lilac bolete. You will learn to identify some poisonous mushrooms so you can be even more careful only to eat safe ones. There are lots of luscious pictures of fungi, many of which will look familiar if you've ever taken a walk in the woods in spring or fall.

To provide incentive for study and hiking, you can wallow in recipes from restaurant chefs, such as Chile Oyster [Mushroom] Soup from Bao Cheng Lee of the Sao Asian Bistro in Marion. Whether you ever hope to gather enough mushrooms for soup or not, you can tote this book out to the woods or your own back 40 and see what fungal treasures are to be found.

My garden, sadly, yields no mushrooms that Greg and Joe consider worth eating. And I probably will not undertake a sufficiently dedicated study to learn to collect cookable quantities of delicious wild mushrooms. (In spring and fall, I will be too busy gardening.) So all I can do is butter Greg up (for example, by writing about his book) and hope he thinks of me some spring in morel season.

Book cover image from the University of Illinois Press

Got a garden question? I recommend you call or e-mail the Plant Clinic of The Morton Arboretum in Lisle, the Master Gardeners of the University of Illinois Extension or the Plant Information Service of the Chicago Botanic Garden in Glencoe.

All contents of this post are copyright Beth Botts. Feel free to link or share a brief excerpt with a link, but please do not reproduce photos or any other part of this blog without my express permission.