Horticulture News: Making sure the grass is greener on your side

By Adam Leonberger, Published:

Home lawn problems have been the number one question at the Extension Office the last several weeks. Crabgrass and patch diseases have been especially problematic for many homeowners. 

Crabgrass is an annual grassy weed that will die out at the first frost. It seeds prolifically in July and has tremendous reproductive capabilities. It is best controlled by two applications of specific pre-emergent herbicides, timed in the early spring.  During the summer months, these herbicides do little to control it. 

Patch diseases and other problems of turf have also been a problem this summer because of high heat and high humidity. These will be small dead areas in your lawn, sometimes with a greasy look, or a light, white, cottony substance on the leaf blade, seen in the morning.

Lawn diseases can have several signs to alert you to a problem. There are also other lawn diseases that are favored in cooler or dryer weather. There are very few lawn fungicides available or recommended for homeowners to combat these problems.  

Crabgrass and diseases are aggravated by excess fertilization; poor timing of fertilizers; too much irrigation; irrigation applied incorrectly; too low or too high mowing height; or planting grass species that is not resistant to disease. 

Proper management is best

The best way to control crabgrass, broadleaf weeds, and lawn disease is to properly manage your lawn.  Fertilize only in the fall; water deeply and infrequently; mow regularly and keep the grass blade height between two and a half to three and a half inches tall; and choose the right grass species that are appropriate for Central Kentucky lawns. These will all be the best ways to keep your lawn looking its best.  

Fortunately, lawn renovation time is upon us. Through September is the prime time to seed, sod, or just start all over again. The following information will get you thinking about renovation and the best way to get your lawn in shape for next year.  

There are several steps to lawn renovation.  These are: appropriate grass variety selection, eliminating weed competition, proper timing of the renovation, proper seedbed preparation and using correct seed planting methods.  

The ‘right’ grass

The “right” grass for your lawn may not be the one you like best, but will be the one most suited to our climate. Turf type tall fescue is the grass of choice for us. Bermuda, zoyzia, Bluegrass, and ryegrasses all have many issues that will cause plenty of headaches down the road. 

Germinating grass seedlings cannot compete with an aggressively growing weed.  For a total kill of the entire area, use a nonselective herbicide like glyphosate (Roundup Pro, Kleenup) or glufosinate (Finale). For other weeds use a selective herbicide for the specific weed.

Or you can mow the turf as closely as possible before renovating. Or heavily dethatching or thinning the lawn by going across it several times with a lawn dethatcher/verticut machine will reduce the competition for new grass seedlings. 

Timing is critical in renovation. As mentioned before, the best time is the end of August to mid-October. Sod can be installed almost anytime there is adequate soil moisture and the sod is available for purchase.

Good soil to seed contact is necessary.  Seeds that lodge in grooves made by hand raking or with special machines, such as dethatchers or slit-seeders, are more likely to germinate and develop. 

Evenly broadcast seed at a rate of 6 pounds per 1,000 square feet. Rake the seed lightly into the seedbed or cross the area again with a dethatching machine.

Watering a must

After seeding, water is a must. Thoroughly soak the newly-seeded area until about one inch of water has been applied. Remember rain counts as irrigation. Be sure not to use fan or oscillating sprinklers during the heat of the day, as the water will evaporate before reaching the ground.

Also be sure water is directed on the lawn and not on your driveway, sidewalk, street, or roof of your house. Do not water at night as this can cause lawn disease problems to develop. 

Once the grass is established, mow frequently to keep the old grass or weeds from shading the new seedlings. As the new seedlings develop, continue mowing to keep the grass between two and a half to three and a half inches tall. Do not let seedlings grow tall before mowing.  

For information on lawn care, log on to UKY’s “Tips and Recommendations for Maintaining Home Lawns” page (http://www.uky.edu/Ag/ukturf/lawns.html) or contact Franklin County Extension, 101 Lakeview Ct., 502-695-9035 by phone or email Adam.Leonberger@uky.edu.

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  • I agree with you, the best odefense against lawn disease is preventative by properly maintaining your lawn. If neglected these seeingly insignificant issues can reverbarate and do serious damage to your yard. For example one crabgrass plant can produce upto 150,000 seeds that can destroy your grass if not rectified. One other point when trying to remove some diseases like crabgrass; its most effective if application of the pre-emergent prevention is used in the Spring before soil temperatures reach below 65 degree.

    Resource: http://www.lawndoctor.com/content/what-is-crabgrass-and-how-stop-it

    Keep the great article coming!