Taking Care Of Your Lawn This Fall—by Rebecca Norman
08-29-2008Taking care of your lawn this fall
LITTLE ROCK - The hot, muggy days of summer have many Arkansans looking forward to fall. As the temperatures cool and daylight hours shorten, homeowners need to make adjustments in their lawn care practices to keep their lawns green and healthy.
Dr. Aaron Patton, extension turfgrass specialist and assistant professor for the University of Arkansas Division of Agriculture, said, “Fall lawn care practices will vary depending on the type of lawn grass - specifically whether it is a warm-season or cool-season grass.” The first step of proper fall lawn care is to determine the type or types of turfgrass found in the lawn.
Cool-season grasses such as tall fescue and Kentucky bluegrass grow best in the spring or fall, when the temperatures are cooler. Warm-season grasses like bermudagrass, zoysiagrass, and St. Augustinegrass have little growth in the fall once night-time temperatures begin to fall below 50 degrees F. Regardless of the type of turfgrass, the following basic maintenance tasks can help protect fall lawns:
* Mowing
* Fertilizing
* Watering
* Weed control
“Fall is a slow time for warm-season lawn maintenance and a busier time for cool-season lawn maintenance,” said Patton. For both cool-season and warm-season grasses, Patton recommended mowing lawns every five to seven days with a sharp mower blade. During times of drought-stress, lawns should be mowed less frequently.
“Cool-season grass lawns should be fertilized with 1.0 pound of actual nitrogen (N) per thousand square feet in mid-September and again in October,” advised Patton. To determine the amount of fertilizer required to apply one pound of nitrogen per thousand square feet, divide one by the first number (adding a decimal before it) in the fertilizer ratio. For example, for a 10-5-5 fertilizer, divide 1 by 0.10. The result is one pound of product per thousand square feet. The numbers in the fertilizer analysis represent the percent total nitrogen, percent available phosphorus and the percent soluble potassium.
In addition to proper fertilization, cool-season grass fall lawns may have additional phosphorus and potassium requirements, both of which can be determined through a soil test. Patton said, “Homeowners should submit soil samples to their county Extension office to determine specific phosphorus and potassium requirements. Lime may also be applied, if recommended.”
Fertilization requirements for warm-season grasses vary from those for cool-season grasses. Patton said, “Don’t apply more than a half pound of nitrogen per thousand feet in September, four to six weeks before the first expected frost. Try to find a fertilizer that contains iron, which will extend color into the fall.”
“Irrigation of cool-season lawns will often be necessary in September but will be needed infrequently for the remainder of the fall,” said Patton.
For warm-season grasses, irrigation is seldom needed during the fall except on newly-sodded areas or in dry, hot, windy conditions. “A bluish-gray color, foot-printing and wilted, folded or curled leaves indicate that it is time to water your warm-season grass lawn,” said Patton. Newly-planted sod should also be watered during the fall to prevent it from drying out.
Cool-season lawns can be renovated for the fall by overseeding thin, bare areas as grass begins to respond to cooler temperatures in September and early October. Patton said, “Use a blend of tall fescue cultivars at eight to 10 pounds per thousand square feet. Apply a starter-type fertilizer at the time of seeding, if soil tests indicate a need.”
Patton suggested that homeowners with cool-season grass lawns apply broadleaf herbicides to control dandelions and other weeds as needed. However, Patton cautioned, “Some herbicides may affect newly-seeded turf. Don’t apply two-way or three-way post-emergence, broadleaf herbicides containing 2,4-D dicamba, mecoprop or triclopyr until seedlings have been mowed at least three times.”
Patton advised homeowners not to apply herbicides designed to control annual warm-season grasses, such as bluegrass, if the lawn is to be over-seeded with ryegrass during the fall.
Patton recommends that homeowners with fall lawn care concerns refer to publications found on the University of Arkansas at Fayetteville turfgrass Web site at: http://turf.uark.edu/. By selecting the Publications link, users can access several Do-it-Yourself publications and fact sheets on lawn care.
More information about lawn care can be found by visiting http://www.uaex.edu or by contacting your county extension agent. The Cooperative Extension Service is part of the U of A Division of Agriculture.