What Do Mushrooms Eat…and Drink? A mushroom is a fungus that can grow almost anywhere. Some mushroom species only grow on certain trees, some grow on logs, Some in decomposing leaves or in compost. Temperature and moisture levels must be perfect for mushrooms to form. So look for them 7 to 10 days after a good rainfall! So just how does a mushroom eat? Well, a mushroom looks like a plant, doesn’t it? And plants perform photosynthesis using water, carbon dioxide, and sunlight to make simple sugars which gives plants energy to grow. But since a mushroom is not a plant, it must find its own food! A mushroom is a fungus. Actually more closely related to an animal than a plant. Unlike animals, fungi can’t run or walk or search for food, can they? Down below the soil or the mulch is the mushroom’s body called the mycelium. This mycelium is made of a web of tiny thread-like strands called hyphae. These webs secrete acids and enzymes to absorb nutrients from dead leaves, rotting trees, and other dead plant matter. The webs can be very tiny or they can stretch for hundreds of feet under the ground…unseen by humans! So, mushrooms are very busy “recycling factories” for dead plants, leaves, and trees. And the mushroom cap that you see above the ground is actually the fruit of the fungus! This fruit grows bigger and bigger just by “drinking” water from the air! Less