Although August usually brings hot, dry days that remind us that summer is not yet over, this month is a very good time to begin thinking about fall maintenance of your lawn. Labor Day weekend is right around the corner and typically signifies the start of fall activities designed to help ensure a lush, healthy lawn, including a minimum of pest issues, for the coming year. Maintenance activities encompass three primary practices.
Aeration involves pulling plugs of soil to open the surface for better nutrient and water movement. Crumble the plugs and let the soil fall loosely into the holes. This procedure helps reduce thatch as well as compacted soil throughout the yard. Aeration is an excellent frontrunner to fertilizing since it allows the nutrients in fertilizers to move more readily into the root zone of your lawn. Aeration helps cool season grasses recover from summer stress and vastly improves grass density and color.
Aeration equipment is available from local rental stores. Keep in mind that machines differ in design. Some aerators use spoon tines to pull soil plugs three to four inches deep on three- to four-inch centers and are considered by lawn care authorities to do an excellent job. However, aerators that force hollow tines into the soil are deemed even better. Regardless of the type of aerating equipment used, any amount of aeration of the soil is better than none.
Over-seeding is the practice of spreading additional grass seed to an established lawn. Use of a power rake prior to over-seeding is recommended to improve contact with the soil, which in turn improves seed germination. Even if your entire lawn does not require reseeding, power raking the small areas where the grass is sparse or completely gone is worth the effort for optimum results. In some instances it may be appropriate to renovate the entire lawn. If so, spraying with an effective weed and grass killer in August will control existing vegetation until the area can be power raked in early September.
Numerous over-the-counter seed products are available to homeowners including both cool-season and warm-season grasses. However, the most prevalent for this part of Missouri are cool-season grasses which are primarily limited to three options: (1) turf-type tall fescue, (2) Kentucky bluegrass, and (3) a blend of the two with a ratio of 90 percent fescue to 10 percent blue grass recommended.
Fescues grow well in full sun to partial shade, develop deeper roots, and thus generally require less water. The Kentucky bluegrasses provide deep color and finer texture. A combination of the two offers the strengths of each while masking the weaknesses of the other. Be wary of any blend that includes 20 percent or more ryegrass; ryegrasses are neither heat nor drought tolerant and they are susceptible to many turf grass diseases.
Before applying any type of fertilizer, begin with a soil test to determine the needs, if any, of the soil in your lawn. Soil pH is important because it affects the availability of nutrients to the grass. Results of a soil test will report nutrient levels, soil pH, and information about lime requirements. Soil test kits with instructions are available at your Pettis County Extension Office.
A wide variety of fertilizers are available including both organic and inorganic types. Look for fertilizers with a good balance of N-P-K (nitrogen-phosphorus-potassium) and with slow-release nitrogen. Fertilizer released into the soil over a longer period of time requires fewer applications and allows the grasses more time to efficiently utilize the nutrients.
For cool-season grasses (not warm-season grasses such as zoysia or Bermuda) apply 2.5 to 3 pounds of nitrogen per 1,000 square feet. Spread the total pounds over two or three applications throughout the fall. For example, after aeration and over-seeding, apply one pound of nitrogen (per 1,000 square feet) in early to mid-September, a second pound in October, and the third pound in November.
These fall practices for lawn maintenance offer a deeper root system and a significant improvement in weed control throughout the following season. Call the Master Gardener Hotline at 827-0519 or contact your local Extension Office if you have questions about the health and beauty of your lawn.