Why Do Mushrooms Grow in Grass?
Mushrooms often look like small umbrellas, which may be one reason they catch people’s eyes and lend themselves to stories of dancing fairies and toad homes. They also can grow straight out of the side of a dead tree, much like a miniature staircase. In actuality, they make up the fruiting body of a fungus whose fine filamentous bodies are running all through the ground or log where mushrooms are seen.
Tip of the Iceberg
Mushrooms can be tiny — about the size of the nail on your pinky finger — or quite large — the puffball can reach 2 feet in diameter. These fruiting bodies of the fungus, however, are not nearly as large as the rest of the fungus that lies beneath the soil. While the body of the fungus is very thin, it is also very long and branched, creating a giant network of fungus throughout many cubic feet of your yard or garden.
What Fungi Eat
As they don’t need sunlight, they can grow almost anywhere as long as there is a dead organic matter to support them. Fungi are one of the main forces that break down dead trees and consume dead leaves, making them one of the most important decomposers on the planet. They show up in your yard because there is dead organic matter in your soil, which indicates that your soil is healthy. Your lawn needs some organic matter to keep the soil aerated and to provide nutrients for your lawn to live on.
The only thing that they need besides dead organic matter is water. That’s why they often appear a day or two after a good rain. One way to reduce the number of mushrooms in your lawn is to stop watering as often. Of course, you can’t stop the rain and you can’t stop watering when you’ve laid out new seed or installed new sod. You can make sure that you remove excess nutrients, like any wood chip mulching you spill on the lawn. And be sure to pick up branches that fall over the winter.
Be careful of any mushrooms that grow in the lawn, if you have young children or dogs. While many lawn mushrooms are edible, a few very common ones — especially lawn-mower’s mushroom (Panaeolus foenisecii) and green-spored lepiota (Chlorophyllum molybdites) — can be deadly. The easiest way to safely control these fungi is to check your lawn frequently and pluck any mushrooms you find. Dispose of the questionable mushrooms where nothing will eat them. Be especially vigilant if the mushrooms are growing in rings, often around an old stump.