Is your lovingly tended lawn unexpectedly spoiled by brown spots, ugly rings, and other misery? Then there are usually lawn diseases behind it. I will explain how to recognize the most common infections and give tips on how to treat them.
Snow mold (Fusarium patch) and typhula blight (Typhula incarnata)
If the lawn stays under a blanket of snow for a long time in winter, snow mold and typhula rot will strike. These are two fungal infections that find ideal conditions at 0 to 8 degrees Celsius (32 to 46F).
You can recognize the diseases by round, grayish-white spots that gradually turn brown. In the absence of approved fungicides, control is limited to the following preventive measures:
- Scarify the lawn every spring
- Sweep leaves and clippings consistently
- Do not use nitrogen-rich fertilizers
The most effective way to combat these lawn diseases is during summer weather. As soon as the mercury column exceeds 20 degrees (68F), the brown spots recede.
Brown Patch (Rhizoctonia solani) and Yellow Patch (Rhizoctonia cerealis)
While beautiful summer weather gives the all-clear for snow mold, the next lawn diseases are already lurking. Brown Patch mars the well-kept green area at temperatures of 25 to 30 degrees Celsius (77-86F), recognizable by rotten-brown to reddish spots.
If the temperatures fluctuate around 20 to 25 (68-77F) degrees, Yellow Patch strikes with yellow-brown spots. Again, prophylaxis is the focus for successful control. That’s how it’s done:
- Sand the lawn after scarifying
- Never water more than absolutely necessary
- Aerate the grass area once a year
If a lawn is infested or threatened by fungi, the irrigation dosage is of additional relevance. Since the fungal pathogens prefer a warm, humid environment, summer drought suits the troubled gardener very well.
Of course, the lawn must be watered so that it does not dry out completely. Therefore, avoid watering, at the end of which puddles form on the lawn.
Fairy ring (Marasmius oreades and others)
In earlier times they were said to have magical powers. In fact, witch rings are a fungal infection that occurs regardless of the weather. You can recognize the lawn disease by the dark green rings in the center of which the stalks turn brown.
In the further course, the grass dies here. This is how you take targeted action against witch rings:
- Loosen the affected areas with a digging fork about 15 cm (5.8 inches) deep
- Fill the resulting holes with sand
- Then spread overseeding and fertilizer on it
In view of the high infestation pressure, you cannot avoid a radical soil replacement. In this case, dig out the damaged areas 15-20 cm (5.8 to 7 inches) deep to fill them with compost and sand. The overseeding is applied over this. It goes even faster by closing the gaps with pieces of rolled turf
The magic lawn patch has proven itself to repair individual damaged areas in the lawn in a short time. Simply remove the dead patches of lawn up to 20 cm (7.8 inches) beyond the ring.
Distribute the lawn paving 3 millimeters thick and water it. The mixture consists of fast-germinating grass seeds, coconut flakes, and fertilizer and thrives on any normal garden soil.