NEIGHBORHOOD GARDEN FOR AUGUST 4

NEIGHBORHOOD GARDEN FOR AUGUST 4, 2012

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LAWN CARE IN AUGUST

BY GEORGE EDGAR

1. Bluegrass can go a long time without water. It will go dormant and turn brown but will not die if the crown gets at least one-fourth inch of moisture at least every 4 to 5 weeks.

“If possible, do not allow tall fescue lawns to go dormant. Tall fescue does not have as good of drought survival as Kentucky bluegrass and will likely thin if allowed to go extremely dormant. Watering with about ¼ inch every two to three weeks on tall fescue may be a good compromise. As tall fescue acreage expands, we’ll learn more. Use deep and infrequent irrigation when watering.”

“In communities with water use restrictions, there could be some dieback in tall fescue lawns. Overseed these areas in early September as needed. Turf-type tall fescue (TTF) will go dormant much later than Kentucky Blue Grass under similar conditions. This is because TTF is deeper-rooted than KBG and accesses water deeper in the profile. Tall fescue actually uses significantly more water than KBG. Tall fescue has poorer drought survival than KBG and thus we usually recommend irrigating often enough to prevent tall fescue from going into complete dormancy. Given the extremely dry conditions, it’s likely impossible to prevent dormancy in TTF. Therefore, we recommend applying ¼” of water every two to three weeks trying to limit damage during dormancy. We’re still unsure how well TTF will survive in summers like this, but the expanding acreage of TTF use over the last few years will give us a better idea after this summer.”

“Regardless of the species, keep all traffic (including mowing) off dormant areas. Even foot traffic will potentially damage the crowns and decrease survival.”

2. Do not fertilize your lawn during July and August, especially Turf Type Tall Fescue. An application of a regular lawn fertilizer about Labor Day, and then a winter or fall lawn food in early October is recommended. The Labor Day and October fertilizations are the two most applications of the year. (3)

This time of year set your mower as high as it will go so the hot sun does not dry out or burn the crown. Let the taller grass provide some shade. Remember the shorter you mow your grass, the more often you have to mow because cutting your lawn stimulates growth, and the more you have to water because it will dry out faster. Also do not pick up your grass clippings. Grass clippings do not cause thatch. They are 90 percent water and if left on the lawn will add the equivalent of one application of fertilizer per year.

(3) August 15th to September 15th is usually the best time of the year to plant new grass or overseed your lawn with Turf Type Tall Fescue and Kentucky Blue Grass.(1). This year the time frame may be a week or two later unless we get normal weather and rains in August. By sewing grass this time of year you will not have competition from lots of weeds waking up, and the soil temperature is warm so grass seed will germinate fast. If you are overseeding your lawn, core aerate to open up the hard clay soil, wait a day or so, and then sow your seed. Rake the seed or pull a piece of chain link fencing over the lawn so the seed drops in the holes.

The worst thing that can happen to the new seed is for it to dry out before germination. This time of year you will have to water at least once a day and if it is hot and dry probably twice a day. Keep the seed moist but not sopping wet. Mulch or some kind of row cover or burlap will help to keep it moist and avoid poor germination.

Buy the best seed you can afford as your lawn will never look any better than the seed you plant. Buy quality seed that is for our Midwest area and disease resistant. If you use disease resistant cultivars you will save money over the long run since you will not have to purchase lots of fungicides to combat disease problems. Look at the package and check the label for the percent of crop seed. Crop seed will look like weeds in your lawn. Also look for the percent of weed seeds. The lower the number the better and zero percent is best. And get a blend of 3 or more cultivars so if a disease wipes out one cultivar it won’t wipe out the whole yard. Grass seed purchased from a local full service garden center or a local supplier will most likely grow better in our Nebraska clay soil and survive our hot dry summers and cold windy winters. Most national brands sold in a box or bag in discount stores, hardware stores, box stores and some garden centers are packaged for sale in many sections of the country and may have been grown in the South. Nebraska certified seed with the blue tag is the best for Nebraska homeowners.

References: (1) “Improving Turf in the Fall” by Zac Reicher and Roch Gaussoin, University of Nebraska-Lincoln Turfgrass Science Program, Publication 2010a, (turf.unl.edu) and “Kentucky Bluegrass Lawn Calendar” NebGuide #G517, by Roch Gaussoin, Robert (Bob) Shearman, Loren Giesler, and Fred Baxendale, University of Nebraska-Lincoln Extension. NebGuide #G517, (www.extension.unl.edu/publications).

(2) “Lawns and summer drought” Hort Update for the Week of

July 27, 2012 (http://byf.unl.edu/web/byf/hortupdate)

(3) “Fertilization for growth and dark green color should be avoided in summer” by Zac Reicher, Turfgrass Science University of Nebraska-Lincoln Extension, June 7, 2012 (http://turf.unl.edu/pdfctarticles/juneoverfert.pdf

(4) “How long will Kentucky bluegrass or tall fescue survive when dormant?” By Zac Reicher, Turfgrass Science University of Nebraska-LincolnExtension,July,1,2012 (http://turf.unl.edu/pdfctarticles/julydormancylawns.pdf)