Q: We had a maple tree cut down about three years ago in our front yard. We have tried to reseed and sow new grass but these mushrooms come up all over the yard. We have dug them up each time before cutting grass.
Can you tell me what these are and how we can get rid of them and keep them from coming back? It seems when my husband digs them up he hits wood under the ground where they are.
A: They’re honey mushrooms, Armillaria tabescens (or Armillaria mellea). The name comes from their color, not their taste.
Another way to think about mushrooms is to call them the “flowers” of an organism that lives underground. In your case, a common fungus has been feeding on dead maple roots. It simply waited for the right weather conditions to “bloom” and send up a mass of mushrooms.
Irrigating your new lawn resulted in good conditions – causing the mushrooms you found. The mushrooms will release fungus spores, but since other spores are naturally found all over your neighborhood, you won’t prevent future mushrooms. Most people just pick them and put them on the compost pile.
You don’t need to dig them before mowing. They will eventually stop emerging, when the tree roots are completely decomposed.