Lawn fungal diseases take on a variety of forms – from
dead-looking brown patches to highly visible spots, threads, rings, or slimes
that can be challenging to treat. A lawn disease targets specific lawn types,
at certain times of the year, under certain conditions.
- Brown patch strikes during hot, humid weather.
- Fusarium blight prefers hot, drought conditions.
- Dollar spot tends to surface when nights are cool, and dew is heavy.
How to Control and Treat Lawn Fungus
The fungus is seen most often at temperatures above 80°F when humidity levels are very high. It spreads through mycelia, which travel from leaf to leaf. Mycelia use water and moisture as a “highway” to move throughout the lawn. Therefore, it’s vital to water in the morning and NOT at night to ensure that water doesn’t stay on the grass leaves too long. Mycelia look like spider webs on the lawn, which appear before damage occurs. If you see these “webs” on the turf, Zaino’s Nursery and Garden Center recommends applying Jonathan Green Lawn Fungus Control, a systemic fungicide used for preventative and curative treatments or Bonides, Infuse Lawn and Landscape, a powerful systemic product that prevents and cures lawn fungus.
Zaino’s Nursery also recommends applying Mag-I-Cal PLUS or Love Your Soil on the same day to increase water penetration into the soil and will limit the “driving” of mycelia. These products work hand-in-hand to control lawn fungus diseases and promote a healthy lawn all summer long.
Tips for a Healthy Lawn
Follow these steps to help take control of fungal diseases in your lawn:
When and How to Water Your Lawn:
Water early in the morning, to allow the grass blades to dry during the day. Give your lawn one inch of water per week, and use a rain gauge to keep track. Water deeply, but less frequently, to encourage stronger roots and to allow the water to absorb properly.
Proper Mowing Height and More:
Mowing at the proper height stimulates a healthy growing lawn to resist fungus. The lawn should not be cut lower than 3". Low cuts and dull mower blades will scalp the leaves and create wounds in the tissue. Such wounds limit the natural ability of grass to resist infection.
Mow your lawn when the grass is dry, particularly if you already have a fungal disease. Keep the mower blades sharp. As stated above, a dull blade inhibits the grass to ward off fungus. Sharp blades, on the other hand, cut cleanly and allow the plant to heal and recover quickly. If you have fungus, try to mow the affected areas last to avoid spreading it.
Aeration is Important:
A layer of compacted soil just 1/4 to 1/2 inches thick can make a significant difference in the health and beauty of your lawn. Aeration creates holes down into the soil to alleviate compaction so air, water, and nutrients can reach grass roots and can be done every year or two.
Apply and rake in a layer of rich, organic top-dressing to improve the soil, increase drainage, and help combat disease.
Remove thick buildups of thatch in your lawn to allow the soil to breathe. Moisture trapped in the thatch layer promotes fungus. If your thatch layer is more than ½ inch thick, de-thatch your lawn in the fall.
Plant Proper Grass Type:
Rather than fighting nature to have an exotic lawn, choose a grass type that’s suited for your climate, soil, and light conditions. Well-chosen lawn types are stronger and able to fight off the normal fungal spore’s native to the area.
Many lawn fungi develop under moist, still conditions. Thin out trees and shrubs to allow air to circulate all over your lawn, and plant shade-tolerant grasses under trees.
Avoid walking on or compacting snow in your yard during the winter, since heavy snow layers can breed snow molds that emerge in spring.