ROOM TO GROW: Answers to fall turf questions
Now that the weather has cooled a bit and folks are getting back out into their yards, the Extension office has had quite a few calls relating to turfgrass issues. Even though we are moving toward the dormant season for the warm season grasses in Middle Georgia lawns, there are several maintenance chores to address now. Here are some of the questions we have received recently.
What are these little moths flying all over my yard?
These moths hide in sheltered spots during the day and the females fly over the lawn in the early evening, scattering eggs as they fly. The caterpillars that hatch from the eggs are known as sod webworms. They are light-colored with dark heads and fine hairs, and they grow to nearly 3/4-inch long. They feed on grass blades.
In fact, a heavy infestation can destroy a lawn in only a few days. Damage tends to become visible in mid-to-late summer and in highly maintained turfgrass. Sod webworms are partial to newly established lawns.
If you suspect sod webworms, you can monitor them using a solution of one ounce of dish detergent in one gallon of water, poured over a one-square-yard area where the infestation is suspected. The detergent irritates the insects, causing them to come to the surface quickly.
Should you see more than 15 larvae, it is time to treat. Insecticides containing trichlorfon, carbaryl or those ending with “thrin” (such as bifenthrin, permethrin, etc.) should be effective. Time the treatment two weeks after peak moth activity, applying it during early evening hours when the webworms are feeding.
I have so many weeds in my lawn. What can I spray on them?
Now is the time that warm season weeds are maturing and producing seeds. Unfortunately at this point, post-emergence herbicides are not very effective on them. The best thing you can do is to keep the grass mowed at the recommended height and to catch the clippings, minimizing the seeds that will fall and germinate next summer.
Using pre-emergence herbicides is a much more effective way to control turf weeds. Although treatment for the kinds of weeds we are seeing now can’t occur until next winter/early spring, now is the time to treat for cool season weeds.The recommended chemical active ingredient is based not only on the type of weeds to be controlled, but also on the kind of turfgrass. Contact your local extension office for specific recommendations.
What formulation of fertilizer do I apply to my lawn now?
It is too late this season to fertilize warm season turfgrasses. The general rule is to never apply nitrogen to lawns in Middle Georgia after August. However, applying potassium (the third number on the fertilizer bag) may help winter hardiness. If a deficiency of potassium is indicated on a soil test, potassium sulfate or potassium chloride can be applied according to recommendations on the soil report.
I have a big dead patch in my yard. What can I do about it?
While fungicides can protect your yard from further disease spread, it is up to you to correct the underlying problems that create an environment for disease to thrive. Ultimately, cultural practices of proper mowing, fertilization and irrigation have everything to do with maintaining a disease-free lawn.
Fall is the time to apply preventative fungicides to slow the spread next spring and summer. As warm season grasses are approaching dormancy and nighttime temperatures are dropping into the 55 degree to 65 degree range, turf diseases are active.
The only way to be sure that you have a fungal disease is to examine the grass under a microscope. If there is a problematic area where disease is suspected, the Extension office can either diagnose in-house or ship samples for a nominal fee to the University of Georgia Plant Pathology Lab in Athens.
Contact your local Extension office for more information on sample collection and fungicide recommendations.
UPCOMING EVENTS
Master Gardeners of Central Georgia Fall Garden Plant Sale: Noon-5 p.m. Sept. 24, 8 a.m.-5 p.m. Sept. 25 and 8 a.m.-3 p.m. Sept. 26, State Farmers Market, 2055 Eisenhower Parkway. Master Gardeners will be available to answer gardening questions. Free admission and parking. For more information, email askamg@mgcg.org or call 478-751-6338.
Contact Karol Kelly at karolk@uga.edu.
This story was originally published September 23, 2015 at 10:14 PM with the headline "ROOM TO GROW: Answers to fall turf questions ."