This year it feels like spring bloomed all the sudden! I don’t know about you, but I’m really enjoying the greenery and wildflowers! I hope you have opportunity to take walks around your neighborhood to see the flowers blooming and trees stretching their limbs with new growth.
The cool temperatures and wet weather of spring can lead to a few turfgrass issues. One fungus that likes to show up in the spring is gaeumannomyces graminis var. garminis. This fungus causes Take-all root rot, a fungal disease that causes weak, dead patches in turfgrass. St. Augustine grass is most affected by take-all root rot, but it can also affect bermudagrass and Zoysia grass.
The symptoms of take-all root rot usually appear in spring and early summer with yellowish grass that eventually turns brown and wilts. The turfgrass thins and leaves brown patches that range in size from one foot to more than 20 feet in diameter. As you can imagine from the name of this fungus, the roots of infected grass turn black and rot.
Take-all root rot lives in the thatch layer of turfgrass, the layer of roots, stolons, and decaying plant matter that lives at the soil surface. The fungus is always present but takes advantage of turfgrass that is under stress from environmental conditions like too much shade, water, or extreme temperatures. Improper management like excessive irrigation, imbalanced fertilization, and improper mowing practices can also lead to conditions that weaken the turf and creates conditions for take-all root rot to spread. The best practice is to encourage healthy root development by watering deeply and infrequently and ensuring good soil drainage. Conduct a soil test and fertilize at appropriate rates, never more than 1 pound of nitrogen per 1,000 square feet per application.
If take-all root rot has infested a lawn, a fungicide should be applied in the spring and fall. Water the lawn thoroughly after fungicide application to ensure it moves into the root zone. Applications of sphagnum peat moss one to two times per year will also help to lower the pH of the soil and prevent the spread of take-all root rot.
For more information about take-all root rot or other lawn management questions, visit the Aggie Turf website at https://aggieturf.tamu.edu/ or contact the Williamson County Extension Office at 512-943-3300.
