While mushrooms will seldom damage your grass, some people do have valid reasons to want to get rid of mushrooms growing in the lawn. First off, some mushrooms are often considered unsightly, especially by those who adore well-manicured lawns. Even if you, personally, do not hold this opinion, it is something to keep in mind if you are preparing your property for the real estate market, for example. You can eat some types of mushrooms (seek expert advice on which kinds are edible), but others are poisonous plants. This is problematic if young children will be playing on your lawn. Pets can also become sick from eating poisonous mushrooms. Some mushrooms even stink badly, the most notorious example being the so-called "stinkhorns."
If mushrooms are left unchecked, the impact from all of these problems may be multiplied. Moreover, while mushrooms usually will not damage your lawn, their presence can signal potential problems for your grass in the future.
The presence of mushrooms may mean that the soil underneath your grass is not draining properly. Poor drainage leads to overly wet conditions, which, in turn, can lead to lawn diseases. In this way, mushrooms are like moss, the presence of which also signals drainage problems (along with problems such as low soil pH and nutrient deficiencies).
Causes for Mushrooms Sprouting Up in Lawns
Mushrooms seem to spring up out of the blue. But this is not really the case. They are just the visible result of a process that has been going on underground for some time.
An underground fungus (with a much greater mass than the mushrooms have) is the true culprit of your mushroom problem. This fungus, often aided by poor drainage and a lack of sunlight, has been spreading as it feeds on decaying organic matter in the soil, examples of which can include:
- Dog or cat poop
- Fallen leaves
- Grass clippings
- Lawn thatch
- Old tree stumps that have not totally decomposed
The mushrooms are merely the reproductive structures of this fungus. Their purpose is to produce spores that can help the plant spread even further.
How and When to Get Rid of Mushrooms
Mushrooms are actually helpful to a lawn in most cases. As the fungus feeds on its decaying organic matter, it breaks this matter down, making nutrients available to your grass. But, if the unsightliness, toxicity, or smell from mushrooms bothers you, there are steps you can take to get rid of them.
Remove the Mushrooms Before They Can Release Their Spores
This method will not solve the problem (because the underground fungus will live on), but it will cut down on mushroom reproduction, at least. Timing is of the essence here: If you are one day too late, the spores may already have become airborne.
Timing is less important to the other three steps we need to take. These steps have to do more with performing landscape-maintenance tasks religiously and monitoring your lawn to ensure that it is not becoming overly shaded or that its soil is not draining properly. These three steps are the ones most likely to solve the problem and consist simply of addressing the three main causes of mushroom problems:
- Poor drainage
- The presence of decaying organic matter
- Too much shade
To improve the drainage in a lawn that drains poorly, there are two common fixes.
Have Your Lawn Aerated
Treating your lawn to aeration may work in less severe cases, and you can rent the equipment from a rental center, since you won't need to aerate enough throughout the year to actually own the equipment.
Install a French Drain
In more severe cases, you may need to install a French drain. Dealing with the presence of decaying organic matter is largely a matter of cleanliness. If you consider yourself a "neat freak," then this step is right up your alley. You will never be able to remove all of the decaying organic matter in your lawn's soil (nor would you want to), but a concerted effort to keep the lawn clean can make a difference in the long run; for example:
- Make spring cleaning in the yard a priority annually.
- While leaving a small amount of finely-shredded grass clippings on the lawn after mowing is generally a healthy practice for your lawn, consider bagging or raking them up if you are intent on keeping mushrooms from sprouting up.
- Rake the fallen leaves off the lawn in fall (or remove them with a leaf blower).
- Keep your lawn de-thatched.
- Remove old tree stumps completely.
Letting more sunlight in to your lawn area may not be feasible if you are surrounded by large trees. But, in less extreme cases, this solution, too, is worth trying. You, yourself may be able to prune small trees just enough to make a difference. For larger trees, hire professionals.