Many different diseases can affect lawns in Florida, including rust, brown patch, take-all root rot, and several different types of leaf spots. Keep an eye on the overall quality of your lawn. If discolored areas appear, this may be a sign of disease.
However, brown or yellow areas can also be caused by other factors like drought or cold damage. Don’t apply any chemicals unless you know what’s really going on.
Large patch is a fungal disease that can affect zoysiagrass and St. Augustinegrass lawns. It shows up as round, discolored patches that expand over time. The borders of the patches are sometimes orange, and the centers appear brown and sunken. It's also known as brown patch or rhizoctonia blight.
This disease often becomes a problem in spring, when cooler temperatures and damp weather create ideal conditions for the fungus. In summer the surrounding lawn may grow, filling in the dead patches, but if the disease isn't controlled, the problem will return again in fall.
The best way to prevent large patch is to care for your lawn properly, since incorrect watering, mowing, or fertilizing practices all make your grass more susceptible to disease.
With recent summers full of rain, Florida homeowners need to be on the lookout for take-all root rot. This fungus naturally occurs on the roots of turf year-round in many lawns, but only becomes a problem with prolonged periods of rain or when a lawn is stressed.
The initial symptoms appear on the roots, but you're unlikely to notice them. If the turf is not being correctly watered, fertilized, or mowed, symptoms will begin to show above-ground as irregular yellow or light-green patches. Then the grass will begin to thin and die. By this time, the damage is done, so your best bet is prevention—avoid overwatering and fertilizing too much or too often.
You can take a sample of grass from the affected area to your local Extension office for identification.
And remember that one of the best ways to prevent disease is to maintain your lawn properly. Follow the UF/IFAS recommendations for mowing, watering, and fertilizing to help ensure you have a strong, healthy, Florida-Friendly lawn.
- Brown Patch
- Homeowner's Guide to Fungicides for Lawn and Landscape Disease Management
- Florida Lawn Handbook: Disease Problems
- Take-All Root Rot
- Turfgrass Disease Management