live in niagara peninsula, st. catharines, very similar climate to toronto, have heard I can use potassium bicarbonate to kill them, was going to start in the spring, how much do I use, and where do I get it from? the yard is @ 50ft x 70ft and do you know if there is any concern re: letting the dog on the yard?
Oh dear, a proliferation of mushrooms can be unsightly. They are actually part of a fungus that grows underground, hidden from sight. The mushroom indicates that a large fungus lies buried in the soil. Lawn fungi and their mushrooms don’t harm a lawn. They break down organic material into nutrients your lawn can use.
The typical umbrella-shaped mushroom, is sometimes called a toadstool. Other types of lawn fungus, including puffball, shaggy mane, Japanese parasol or the oddly-shaped and smelly stinkhorn.
When mushrooms appear on the lawn, break them off or mow over them. If you have pets or children who might be tempted to eat the mushrooms, gather the broken pieces and dispose of them.
A fungus grows by breaking down organic matter. In a lawn, that organic material could be buried timber, a stump, or tree or shrub roots that remain underground after plants have been removed.
In most cases, when the fungus has finished breaking down the buried organic matter, the fungus (and accompanying mushrooms) will disappear.
If you don’t mind disturbing your lawn, you can also try digging up the organic material.
Use of nitrogen fertilizer can mask the symptoms by causing the rest of the lawn to become very green.
There may be organic fungicides available for suppression of mushrooms. These fungicides may be only temporary in measure as the decaying material may still be present.
Periods of prolonged rain can cause mushrooms to form, as can overwatering a lawn. Heavily compacted soil and a thick thatch layer can create drainage problems, which provide ideal growing conditions for mushrooms.
While not all lawn mushrooms thrive in shady conditions, many do. If a corner of your yard offers high soil moisture combined with low light, mushrooms may appear.
Address the moisture issue using one of the techniques listed above. If trees shade the lawn, tackle light tree trimming to allow more light to reach the grass.
Here are are some links which will provide additional information on mushrooms and treatment.
https://www.weekendgardener.net/plant-diseases/mushrooms-090809.htm
Good luck in treating the mushrooms in your yard.