Why Have All These Mushrooms Appeared on My Lawn?

It’s a common question we get asked a lot ‘why do I have mushrooms growing in my lawn?Cool, damp weather after bouts of high heat encourages mushrooms to grow in lawns in Ontario. High, lingering overnight humidity and dampness is also an open invitation to fungus growth causing mushrooms that grow in grass to appear, so we strongly discourage watering in the evening.

After some long and heavy soaking rains, normal in Late August and September, we see an unusual amount of mushrooms sprouting in Ontario lawns.


Why are mushrooms growing in your yard? Because fungi are nature’s garbage crew. Mushrooms in your lawn are working to break down dead organic material and freeing up those nutrients for your grass to use.

Lawn mushrooms are just the fruiting bodies of the fungus. They’re the part that pops up above ground in your grass to spread spores around. Most of the mushroom in your grass is actually underground, busily eating up old bits of wood, dead grass, and leftover roots of plants that have been removed. Even animal poop is fair game for fungus.

Removing Mushrooms In Your Lawn

If you have mushrooms growing in your lawn you can easily kick, stomp, mow or rake them as they appear if you want rid of them. They will grow back though, as long as whatever organic decay the fungus is eating is in your soil, and the area is warm and damp enough for the fungus to grow.

If there is an old stump, root or buried construction debris, digging it out will remove the main source of your mushroom problem in your lawn.

mushrooms in lawn vaughn ontario

Fungus colonies grow outwards, forming “Fairy Rings” of mushrooms at their edges.

How To Keep From Getting Mushrooms In Your Lawn

Because Ontario has such variability in weather patterns we normally experience  times of year that are particularly conducive for mushroom growth in lawns. Good lawn cultural practices are still the best way to make your lawn unappealing to mushrooms. This is what the lawn experts here at LawnSavers recommend:

  • Mow regularly so thatch does not build up. Do not leave long clippings (greater than 1″) on the lawn as thye are a big contributor to excess thatch!
  • Aerate every year – the improved drainage and airflow that this practice develops will help prevent the soil from creating the condition of lingering dampness that mushrooms love. LawnSavers can do this for you in Spring or Fall, starting at just $84.00 + HST. We service lawns throughout the Greater Toronto Area
  • Only water your lawn once a week- deeply, so your lawn has time to dry out in between lawn waterings.
  • Rake up any leaves, old mulch or other debris promptly so it doesn’t become fungus food.
  • Clean up ‘pet poop’ regularly, the leftovers from feces left to decompose into the grass is a prime spot for mushrooms to grow.

If you’ve got mushrooms growing in your lawn LawnSavers is an award-winning lawn care company in Ontario that can help with mushroom issues or any other pest that could be causing your lawn to look less than perfect. Contact us today if you are looking for help with your lawn.

FAQ About Best Lawn Care Practices

🌱 How Many Times a Week Should You Water Your Lawn?

Take the advice of the grass experts at LawnSavers, you need to water at least once a week for at least an hour, this generally provides 1-1.5″ of water to the roots (a tuna cans height) (exceptions: 1. when you seed &  2. if you have an automated system 3. When we are experiencing extreme heat).
New Seeding Watering: Seed must be kept moist until established.  This will be influenced by the amount of sun, wind, and heat you are experiencing in your particular area.  It is normal to require 3-4 short waterings per day to maintain a moist seedbed.  Use a light stream of water to lessen disturbance of the seedbed.

🌱 What is Aeration?

Natural aeration is the process of air exchange between the soil and its surrounding atmosphere. Sometimes this process needs a little help, and that is where liquid aeration, the process of either applying a blend of soil enhancing materials OR mechanically removing small plugs of thatch and soil from the lawn, is used to improve soil aeration.

🌱 What is the Proper Height to Mow Grass To Keep It Healthy?

In the spring (May-June) and fall (September-November), your lawn should be kept at the 2.5 – 3-inch mark and in the hotter and drier summer periods at least 3 inches.  Contrary to popular belief, if you cut the lawn shorter it doesn’t make it grow at a slower rate, it can actually cause it to lose moisture and scorch.