Grass rust is a fungal disease that causes yellow spots on the leaves of your grass.
If left untreated, it can cause severe leaf damage and even kill off chunks of your lawn.
How do I know if my lawn has grass rust?
If you notice yellow spots on the leaves of your grass, chances are you have grass rust.
You may also notice dead patches in your lawn where there used to be healthy green blades.
Grass rust usually appears during the summer months when temperatures are high and humidity levels are low. It is most prevalent in dry areas with warm climates.
What causes grass rust?
Grass rust is caused by a fungus called Puccinia graminis f.sp. tritici (Pgt). The Pgt fungus overwinters in infected plant debris or in soil and releases spores in spring when the weather becomes warm and humid enough for infection to occur.
The spores infect young leaves, causing small yellow spots to appear on them within 2-3 weeks after infection occurs.
If the weather remains hot and humid, these yellow spots will grow larger until they cover most of the leaf blade surface area or kill off whole patches of turfgrass leaves, leaving bare spots where there was once healthy green turfgrass.
The fungus will spread from infected leaves to healthy ones through windblown spores which land on new growths.
Once infected, the entire leaf blade will turn yellow and die prematurely, resulting in brown patches throughout your lawn that may take several years to recover from completely if they are not treated properly.
How do i get rid of grass rust?
The best thing you can do to prevent grass rust is to make sure your lawn does not get infected in the first place.
Rake up and remove all dead leaves, stems, and plant debris from your yard every fall so that they will not come into contact with the soil.
Do not mow your grass too short, as this will give the fungus more opportunity to spread through windblown spores.
Apply a fungicide containing chlorothalonil or mancozeb (Daconil®) at least 3-4 times throughout the summer to prevent infection.
If you notice any yellow spots on your grass leaves during the growing season, apply a fungicide immediately to prevent the disease from spreading any further.
If you’re reseeding your lawn, you should also reseed with a rust resistant variety.
Rust resistant varieties are available from most major lawn seed companies, or you can ask your local lawn care company for a recommendation.