Fungi in the lawn are usually not a serious threat, but they can disturb the appearance of the lawn. Below we present the most common fungal diseases affecting lawns and which countermeasures are suitable.
When it comes to fungi in the lawn, a distinction is made between fungal diseases and hat fungi.
Cap fungi, which sometimes appear very suddenly and in heaps in the lawn in late summer and autumn, are usually completely harmless to the lawn, while fungal diseases can kill entire sections of the lawn.
However, fungal diseases are not critical or worth fighting immediately in most cases. Many will soon disappear of their own accord with a change in weather conditions.
Here is a brief overview of a selection of fungal diseases and cap fungi that frequently occur in lawns:
|lawn rust||redpoint||snow mold||dollar spot disease||slime molds|
|appearance characteristics||Rusty-looking yellowish-orange patches on grass blade blades, mottled overall lawn appearance||Dried-looking lawn islands, reddish leaf tips||Light gray to light brown patches in the lawn, leaves stuck together after snow melts||Small dried spots in the lawn||Small, greyish-whitish, black or yellow slimy deposits in the lawn|
|Educational conditions/at what times of the year||Warm, humid weather in summer||Lack of nutrients, all year round and especially in summer with high humidity||Humid, moderately cold weather in winter||In summer on permanently very short lawn||In summer in warm, humid weather|
|countermeasures/prevention||Waiting for dry weather/Regular mowing, watering and fertilizing||Fertilize, do not dispose of lawn clippings on the compost||Regular aeration by scarifying and sanding, fertilizing in autumn||Water more rarely, but extensively, aerate well (scarify, sand), fertilize with potassium in early summer||Because it is harmless, no countermeasures are necessary. Scarify, fertilize and water regularly as a preventive measure|
|phonies||Navellings||Tintlinge||Bald Krempling||Alkaline rouge|
|Look||Small, round mushrooms with thin-fleshed, brown to white fruiting bodies||Small, brown mushrooms with umbrella-like, centrally sunken, roughly lamellar fruiting bodies||White mushrooms, acorn-shaped, later bell-shaped fruiting bodies when young, turning black with age||Brown-reddish to yellow mushrooms with a medium-sized lamellar cap, relatively fleshy||Light brown, sometimes white or red mushrooms, tall stem, flat, sunken to humped umbrella|
|Edible?||Some species edible||Most species inedible||The Schopf-Tintling in particular is an excellent, mild-tasting edible mushroom||No – toxic||No – toxic|
|Tendency to witch rings||Especially the carnation swindler||no||no||no||Yes|
Correct removal of fungi in the lawn
Many fungal diseases are not a threat to the lawn and will clear up on their own when the weather changes. Even a period of warm and humid drizzle is over at some point.
When it gets drier again, lawn rust, redness, and slime mold usually go back quickly, and snow mold is also pushed back as soon as it gets warmer and drier again in spring.
The best way to combat dollar spot disease is to water less frequently and more extensively and deeply. In this way, the lawn can be supplied with sufficient moisture but still has the opportunity to dry well in between.
Basically, you can counteract fungal diseases in the lawn primarily by preventing them. The best way to do this is through the usual care measures that keep the lawn resilient and healthy. So you should regularly:
- Aeration by scarifying and sanding
How intensively and how often you have to scarify or sand depends on the site conditions and the soil properties. A heavy loamy soil in a shady location naturally tends to be permanently wet and acidic, which on the one hand creates favorable conditions for fungi and moss and, on the other hand, weakens the lawn grass and makes it more susceptible to infections.
For these measures, it is best to use the visual signals of your lawn as a guide.
Watering is a sensitive matter in terms of preventing fungus. On the one hand, the lawn needs an adequate water supply to be healthy, but on the other hand, it becomes susceptible to fungi if it is too wet.
Therefore, only blast it during prolonged dry periods in summer, preferably in the early morning hours or in the evening when it is no longer directly exposed to the sun.
It is advisable to give it a slow-release fertilizer once in spring and again in late summer for general lawn health. To avoid snow mold in winter, it is important to use a potassium-rich fertilizer in the fall.
In the period of a fungal disease, mow around the infected areas of the lawn if possible first and cut them last. This will prevent the spores from spreading to areas that are still healthy. Dispose of the clippings in the household waste until the fungal disease has subsided.
If a homogeneous, tidy lawn is important to you, excessively sprouting mushrooms are, of course, annoying. Most species found in garden lawns appear as small brown, grey, white to orange mushrooms. However, cap mushrooms do not invade the grass plants with their underground mycelium or their fruiting bodies, so they are really only a cosmetic problem.
With cap fungi, it often happens that many mushrooms suddenly appear on the lawn overnight. First of all, that’s nothing to worry about. Only when they form so-called witch rings can discoloration and drying damage occur.
Suitable countermeasures are as follows:
- Remove the food base from the mushrooms
- Tear open the mycelium with a fork
- earth exchange
Remove food source
If you want to remove cap fungi permanently, you must carry out continuous cutting and scarifying care. It is best to mow regularly with a grass catcher and reduce the lawn thatch by scarifying in a grid-like manner. This deprives the mushroom mycelium of the food basis. In addition, it helps to loosen and aerate the soil by sanding.
But be careful: mowing alone does not help with cap mushrooms. On the contrary: They only promote the spread of the spores, while the actual fungus, the subterranean mycelium, remains undamaged. As a result, all the more fruiting bodies then shoot out of the ground.
Targeted damage to mycelium
You can also put your hands on the fungus areas in a very targeted manner: Arm yourself with a digging fork, pierce the soil several times at the fungus-infested areas and lift it slightly. This can tear open the mushroom mycelium and cause it to die.
In the case of clearly defined fungal areas, especially in the case of witch rings, an earth exchange can also be considered. To do this, remove the top 30 cm (11 inches) of the soil layer, fill it up with fresh soil and reseed with grass seed of the highest possible quality.
In order not to spread the spores of cap fungi unnecessarily, it is advisable (in addition to disposing of the clippings in the household waste) to remove the fruiting bodies by hand before mowing. If it’s an edible species, collect something for lunch at the same time.
In most cases, you should not and cannot work with fungicides. No chemical agent is permitted for many fungi that occur in garden lawns. This applies in particular to the cap fungus species.
Quite apart from that, it is generally not advisable to use chemical agents, herbicides, and fungicides to control unwanted phenomena in the garden. You upset the biological balance of your garden and that of the wider environment.
Causes of fungus in the lawn
The causes of fungi in lawns and beds are relatively diverse and are not limited to favorable growth conditions for the fungi. Certain site conditions and care habits can also make the lawn too susceptible to it.
The main causes of fungal diseases and annoying cap fungus accumulations are as follows:
- Lawn and air permanently too wet
- Too little light
- A matted, poorly aerated lawn
- soil acidification
Long-lasting temperatures of 20 to 30°C (68-86 F) and constant, drizzle or wet weather in winter create optimal conditions for various fungal diseases. As with all fungal diseases on plants, too humid conditions are the decisive cause of the emergence of fungi in the lawn.
If it is permanently too wet, fungi feel particularly comfortable on it. Above all, warm, humid phases in summer with stagnant air are responsible for some fungal diseases.
Cap mushrooms also like it moist. The risk of fungal growth is particularly high under trees, with which many species form mycorrhizal symbioses and under which moisture lasts longer.
Too little light
A lack of light does not necessarily promote the spread of fungi, but it weakens the lawn and thus increases its susceptibility to fungi.
Under tall, densely crowned trees, the lawn grasses cannot form a strong turf and become porous and permeable to dreaded combinations of disturbances such as fungi plus moss and fungi plus weeds.
If a dense thatch has formed through years of neglected care without regular scarifying, watering, mowing, and fertilizing, the lawn can no longer breathe, making it weaker and less competitive.
On the other hand, the lawn thatch forms an ideal breeding ground for fungi. As a prevention against fungi and also in the case of an existing fungal infestation, grid-like scarifying is helpful, with which the lawn thatch is combed out.
Despite good lawn care with sufficient aeration, watering, and fertilizing, many mushrooms shoot out of the ground; this can be due to soil acidification. Check if the pH is below the lower limit of 5.8 with a simple soil test. If that is the case, offset the value with lime according to the package instructions.
What times of the year do fungi appear on the lawn?
Mushrooms are mainly associated with autumn. However, this association mainly relates to the world of edible mushrooms. But when we talk about fungal diseases in the lawn, summer is the more important season.
This is because many common fungal lawn diseases develop in warm, humid conditions. Fungi, which are less to be regarded as a disease but can disturb the appearance of the lawn – above all-cap mushrooms – actually mainly appear in autumn. On the other hand, Isolated fungal diseases only occur in winter, even under a closed snow cover.
Avoid care mistakes
Regular watering is a perfectly correct care measure for a healthy, well-groomed lawn. But you shouldn’t overdo it either. If the lawn doesn’t get a chance to dry between blasting, lawn rust and red spots have an easy time, especially at temperatures in the 20s (68F).
So only irrigate your lawn during prolonged dry periods and preferably in the early morning hours, when the sun is not yet scorching the grass, but its first soft rays can dry it gently.
Too much or wrong mulching
In principle, mulching the lawn is highly recommended. If you mow frequently and leave the clippings lying around, all the nutrients stay in the lawn soil and can be reused. So you need to supply less additional fertilizer.
The activity of microorganisms living in the soil is also stimulated. The turf is compacted, so that typical combinations such as mushrooms plus moss and mushrooms plus weeds have fewer chances.
Studies have shown that mulch mowing makes the lawn significantly stronger and more vital than conventional mowing (where the clippings are collected in the lawn mower’s grass catcher).
In order for the advantages of mulch mowing to take effect, however, the method must be used correctly. This means that you have to mow regularly and at short intervals (preferably weekly during the growing season).
The lawn should also be as dry as possible and free of other organic material such as fallen leaves when mowing. Clippings that are too long or stuck together with leaves can also clog the lawn and lead to a lack of light and air. This, in turn, weakens the lawn and increases its risk of infection.
Regular fertilization is recommended for a strong lawn that is more resistant to fungal diseases. But you can also mean too well with the fertilizer application – when it comes to fertilizing, the rule always applies anyway: less is more.
Especially if you fertilize too much nitrogen in the fall, this can quickly lead to snow mold in winter. Long-term fertilization twice is ideal for a lawn area, once in spring and autumn. In autumn, you should use a potassium-rich preparation.
frequently asked Questions
Which mushrooms in the lawn are edible?
Only a few types of the most common hat mushrooms found in lawns are edible. In addition, most of them are not very suitable for a decent, substantial mushroom ragout because of their puny size.
However, the real garlic swindle is often used as a seasoning mushroom, especially in France, for example, in dried form.
The spicy-sweet-tasting cloves can also be eaten, which is the best way to counteract its harmful effects on lawns. It is particularly good in mushroom soups, for example.
Tintlinge are also excellent edible mushrooms and are also richer in substance due to their size. They’re great eaten raw in salads or pan-fried.
But you should harvest them in good time before the hat opens up and secretes the eponymous black ink liquid for self-digestion.
If you’re lucky, the kings of edible mushrooms, meadow mushrooms, may also settle in your garden lawn.
The versatility of their usability needs no further explanation. However, extreme caution is required due to the slight risk of confusion with the highly toxic death cap mushroom.
Are there home remedies for fungus on the lawn?
Using home remedies in the garden is generally not particularly advisable. Many of the remedies in the household often have more ecologically problematic side effects than harm-reducing benefits against unwanted phenomena in the garden. No special home remedies have proven effective against fungi.