Grass Fungus
Common Causes of Grass Fungus
Nothing ruins your lawn like grass fungus. No matter how much time and energy you put into your lawn each year, you can still be susceptible to fungi. Fungi are thread-shaped microscopic organisms that spread through spores. Anytime spores are present, and they can be carried by wind or water, and the conditions are right fungus can grow. Indentifying the type of fungus that is growing on your lawn will allow you to remove it, treat it with fungicides and take preventative steps to avoid a future outbreak. Listed here are some characteristics of the most common forms of grass fungus.
A brown spot that is shaped like a horseshoe and continues to grow larger could be a fungus called Brown Spot. (It can also be known as Rhizoctonic Blight) Brown Spot occurs in areas of shade and high humidity.
Dollar Spots are small brown or yellowed colored patches that resemble silver dollars, but increase in size. They often occur in humid climates with wet warm weather and soils with lower levels of nitrogen. Excessive nitrogen in soils can cause a condition called Leafspot, where spots appear in individual leaf blades.
Fairy Rings are round rings of dark green colored grass that often contain mushrooms. They appear to get worse as the grass turns darker.
Slimy patches of grass with a white fungus growth on top are usually referred to as a Grease Spot. They occur mostly in very humid climates.
Snow Mold takes the shape of gray or white looking grass that sticks together. It often appears to be fuzzy and soft. It occurs from snow sitting on top of the grass for a long period of time and appears after the snow begins to melt. It is the result of improper drainage and lack of aeration.
Rusty colored spots on grass leaves that grow in dewy, shaded areas are caused by a fungus called Rust. Damp areas with a low fertility rate are susceptible to rust. In moist, cool climates reddish colored spots that can eventually turn brown are the result of a condition known as Red Threat. Grass that grows in shaded areas can become infected with Powdery Mildew, named for the white dust like growth is displays. Another white, powdery substance that grows on grass is a type of mold, referred to as Slime Mold. Grass infected with slime mold will eventually turn yellow.
Too much mowing when the grass is too wet can result in Pythium Blight. This condition takes the form of spots of wilted brown grass. Summer Patch (also called Fusarium Blight) creates donut or c-shaped patches of light green grass. These patched will eventually turn brown. Summer Patch can kill grass.
Grass that appears to split down the center and grow in patches of thin, uneven growth is often infected by Stripe Smut. Stripe Smut occurs in cool weather conditions and turn grass color to gray then to black. Sunken or depressed areas of grass with reddish colored blades can result from Necrotic Ring Spot.
Once your lawn has been infected by any of these forms of grass fungus, the best way to treat and remove the problem is with fungicides. There are many fungicides available at the local home improvement store or garden center and they can cover a wide array of fungi types. Be sure to read and follow the directions of each kind of fungicide to prevent doing further harm to your lawn. Broad-spectrum fungicides are available, but you will want to careful with them as they can kill both good and bad organisms. It is best to use fungicides on specific spots first to determine how they will affect your lawn. There are three types of fungicides you can use, contact fungicides, systemic fungicides and penetrant fungicides.
Contact fungicides remain on the grass surface and kill any spores that come into contact with it. Systemic fungicides enter into the plants entire system, including the roots and lasts longer than contact fungicides. Penetrate fungicides all enter all the plant’s systems and remain as a preventative measure.
By using fungicides to treat your lawn and by practicing some basic preventative lawn care steps such as following the correct watering amounts and times, a proper fertilizer schedule, creating proper lawn drainage and regular mowing, you will be able to keep your lawn clean and green all season.