For lawn care for the month of August, homeowners should continue their regular routine of mowing every 5-7 days and less often when the lawn is drought stressed.
Continue to monitor for insect pests and apply post-emergence herbicides as needed to control summer broadleaf weeds. Apply herbicides when weeds are present and the lawn is actively growing.
As for diseases, you need to monitor for them as well. One of the most important diseases of turf is Large Patch. Bermuda, St. Augustine, and Centipede are all susceptible. Even though the actual damage occurred earlier in the year, we are seeing the visible signs of the disease now. Stolons and basal leaf sheaths develop water-soaked black to reddish-brown lesions. Irregular circular patches develop that may be from several feet to more than 25 feet in diameter. Sometimes a smoke colored or orange halo may be observed early in the morning at the margins of the patch. Diseased shoots are easily detached from their points of attachment. Roots are discolored but not rotted. In the most badly affected turf, entire lawns may be blighted. Symptoms on Bermuda usually occur earlier in the spring than on Zoysia. Symptoms in Zoysia occur two to eight weeks after green up, or in the autumn. Sometimes symptoms slowly disappear during the growing season as surviving tillers start filling in the killed spots. Night irrigation, shade, and excessive amounts of nitrogen increase both severity and incidence of patch diseases.
Complete fertilizers with time-released nitrogen should be used instead of quick release nitrogen. Apply 0.5 pound of nitrogen per thousand square feet approximately three weeks after the grass turns green in late May. No more than two pounds of nitrogen total should be applied per growing season to Zoysia. A soil test is useful to see where fertility levels are. Good drainage is essential for a healthy lawn. The turf should be de-thatched if thatch accumulates to more than 0.5” thick. De-thatching should be done while grass is actively growing. Fungicides may be applied once in the spring between March 15 and April 15, and again in the fall between September 20 and October 10. Heritage, Prostar, Eagle, Instrata, and Bayleton are labeled for Large Patch. Take a soil sample for pH and nutrients. Avoid night watering. Homeowners may use Spectracide Immunox Plus Insect Control for Lawns, Scotts Lawn Fungus Control, or Bonide Infuse Systemic Disease Control for Lawn and Landscape.
For more information on lawn care, contact the Phillips County Extension Office at 870-338-8027.