Stains on the lawn are unsightly to look at. A fungal infection is often a possible cause. The species attack grasses when they are weakened and suffer from suboptimal care. A lack of nutrients or drought improves the growth conditions of fungal spores.
What to do if there is a fungal infection in the lawn?
Snow mold, red tip, lawn rust and dollar spot can occur when a lawn is infested with fungus. Preventive measures include a balanced water supply, regular scarifying, good nutrient supply and an appropriate cutting height of the lawn.
Snow mold
The gray-brown and putrid spots in the lawn reach sizes between five and 25 centimeters. Over time, the areas grow together and the gray to pink mycelium of the fungus Fusarium nivale can be seen at the edge areas. An infestation often occurs in September or spring when there are cool temperatures below ten degrees combined with high humidity. If snow cover lasts for a long period of time, the growth of the fungus is further promoted.
Preventive measures
Avoid waterlogging and high humidity in the lawn. By scarifying and sanding you improve the aeration of the top layer of soil. Autumn fertilization with agents containing potassium and magnesium strengthens grass growth and makes it more resistant to fungal attack in the cold season. When temperatures rise in spring, the fungus automatically declines. The grass grows back and fills the gaps. If the lawn does not grow through larger areas, you can spread new lawn seeds on the bare spots.
Red-tippedness
Laetisaria fuciformis develops reddish threads on the affected leaf tips. The fungus requires high humidity and temperatures between 15 and 20 degrees. Therefore, this lawn disease occurs predominantly in summer and autumn. The fungus is considered a weakness parasite and attacks undernourished grasses. In the advanced infestation stage, the lawn appears yellowish mottled.
How to proceed:
- administer a slow-release fertilizer directly
- Apply four to six grams of nitrogen per square meter
- Dispose of lawn clippings in household waste
Lawn rust
Various species of the genus Puccinia cause yellow nests in the lawn. Yellow-brown to black pustules can be seen on the grass. Since the lawn disease spreads in warm climates with 20 to 30 degrees and dryness, you should ensure a balanced water supply. A long-term fertilizer makes the grass species more robust.
Dollarspots
Sclerotinia homoeocarpa causes clearly defined spots about the size of a coin. These appear pale and are covered in white mycelium. This permanent spot disease occurs more frequently in high summer temperatures between 25 and 30 degrees in very short-cropped lawns. The formation of dew at night promotes fungal growth, as does nutrient deficiency and soil dryness.
You can do this
Drought stress damages plant he alth, making grasses more susceptible to fungal diseases. Even smaller areas should be irrigated regularly during hot periods. Water the lawn thoroughly in the morning hours. Make sure there is a sufficient supply of nutrients and, if necessary, remove thatch with a scarifier (€118.00 on Amazon).
Tip
Cap mushrooms are not dangerous for the lawn. Their spores spread in the air and germinate upon contact with the ground when conditions are optimal. By regularly scarifying, you deprive the fungi of their growth base.