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Lawn mushrooms

mushroom Marasmius Oreades

Mushrooms are a common occurrence on lawns across Calgary.

Also known as "toadstools", mushrooms develop on decomposing grass leaves and dead tree roots and tend to appear after heavy rains or watering. The fungi that produce mushrooms are harmless to grasses – in fact, most of these fungi are beneficial. They break down organic matter and release nutrients that are necessary for plant growth – but you may consider the mushrooms unsightly.

How to get rid of lawn mushrooms

There are no chemicals (fungicides) that are effective in controlling mushroom-producing fungi, so you'll need to use cultural methods to control them.

  • Where practical, carefully dig up and destroy rotting stumps, roots, or other organic debris.
  • If excessive thatch (organic material that sits above the surface of the soil) is causing the problem, dethatching the lawn in fall is the best solution. Dethatching removes the fungi's food source.
  • You can also remove mushrooms by hand, with a lawn mower or stiff rake.
    Mushrooms will disappear naturally only when the food in the soil becomes exhausted. This process may take several years.

Warning: some mushrooms are poisonous

Do not eat wild mushrooms or other fungal fruiting bodies unless you are well acquainted with the different species. Many species are poisonous and only an expert can distinguish between edible and poisonous species. There are no simple tests that can be used to identify poisonous mushrooms. It's important to keep an eye on pets and small children when mushrooms are present.