Feb 27, 2020

Now’s the time to prep for healthy summer lawns

Posted Feb 27, 2020 1:08 PM

MANHATTAN – It’s probably a bit early to hope that the cold days of winter are in the rear view mirror, but homeowners with dreams of a lush summer lawn should already be concocting their spring work schedule.

“Now’s a good time to make a lawn care plan,” said Ward Upham, a K-State Research and Extension specialist in horticulture. “I suggest marking dates on a calendar so that important tasks are not forgotten.”

A majority of Kansas homeowners grow such cool-season grasses as bluegrass and tall fescue. In the southern and western parts of the state, Bermuda, zoysia and Buffalo grass are popular warm-season grasses.

Upham, who for nearly 30 years has answered homeowner’s questions through the university’s Horticulture Information Center, said the months leading up to summer are crucial for setting up the home lawn for success.

“Fertilizing at the correct time can help prepare our cool-season grasses for the stresses of summer,” Upham said. “If you fertilize too little, the turfgrass plants enter the summer in a weakened condition. If you fertilize too much, the plant responds by growing faster, which leads to mowing more often or removing too much of the leaf blade at one time.

“Follow guidelines so that you fertilize at the correct time and with the correct rate, which leads to healthy plants that are better able to fight off disease and weed invasion.”

K-State publishes a weekly horticulture newsletter with tips to help home gardeners maintain healthy landscapes. The Feb. 18 issue outlines a schedule to help homeowners care for their lawns.

For cool-season grasses:

March – spot treat broadleaf weeds, if necessary. Weeds should be treated on a day that is 50 degrees F or warmer. Do not water the lawn for at least 24 hours.

April – Apply crabgrass preventer when redbud trees are in full bloom. The preventer needs to be watered in before it will start to work. One-quarter inch of water is enough.

May – Fertilize the lawn with a slow-release fertilizer if you water your lawn, or if you normally receive enough rainfall that the lawn doesn’t go drought-dormant during the summer. Spot treat broadleaf weeds with a spray or use a fertilizer that includes weed killer. Rain or irrigation within 24 hours will decrease the effectiveness of the weed killer, but fertilizer needs to be watered in. If using a product with both fertilizer and weed killer, wait 24 hours before watering.

For warm-season grasses:

March – spot treat broadleaf weeds, if necessary. Weeds should be treated on a day that is 50 degrees F or warmer. Do not water the lawn for at least 24 hours.

April – Apply crabgrass preventer when redbud trees are in full bloom. The preventer needs to be watered in before it will start to work. One-quarter inch of water is enough.

May – August 15 – Fertilize with one pound of nitrogen per 1,000 square feet per application. Follow the recommendations on the bag.

“More applications will give a deeper green color, but will increase mowing and lead to thatch buildup with zoysia,” Upham said. “Bermudagrass can also have problems with thatch buildup but thatch is less likely with Bermuda than zoysia.”

Upham suggested that homeowners should plan on two to four applications of fertilizer for Bermudagrass, and one to two for zoysia and Buffalograss. He offered the following guidelines to determine when to apply fertilizer:

One Application: Apply in June.

Two Applications: Apply May and July.

Three Applications: Apply May, June, and early August.

Four Applications: Apply May, June, July, and early August.

For a complete lawn care schedule stretching through November, subscribe to K-State’s weekly horticulture newsletter, which includes information on fruit, vegetables, trees and a variety of other landscape topics.

Interested persons also can visit K-State’s Horticulture Information Center online, or send email to Upham at [email protected].