Is it time to feed my lawn?

ASK THE HORT AGENT

Question Is it time to feed my lawn?

Answer The concept of “feeding” your lawn is misleading. Grass does not have a mouth: therefore, it does not eat. You can feed pets, birds, alligators or bears, but not turf.

If you buy into the “feeding” concept, then think of fertilizer as calories. Imagine your lawn is a professional boxer. It has to be in shape. An overweight or a skinny boxer probably won’t make it 15 rounds.

Fall fertilization depends on the type of grass in your yard. Cool season grasses begin to grow in September. Fescue and rye grass are cool season grasses. As they grow, then a demand for fertilizer is created. The addition of one pound of nitrogen per 1,000 square feet is the standard recommendation for cool season grasses in September.

Some companies sell “weed and feed” products. The “weed” part is an herbicide which is supposed to kill weeds. Of course, the “feed” part is simply fertilizer. These products can be very useful on fescue lawns. However, make sure you apply these products AFTER your grass seeds have sprouted. Some “weed and feed” products contain a preemergence herbicide which doesn’t know the difference between the fescue or chickweed seeds.

Fall fertilization has a different meaning for warm season grasses like centipede, zoysia or St. Augustine. These grasses are shutting down, not cranking up. They do NOT need nitrogen in September. Tender growth in September will get zapped by the frost in October. However, there is a nutrient that will benefit them greatly. It is potash (or potassium).

Potassium (or K on the periodic chart) does not encourage new growth. Instead, it helps the grass defend against drought, disease and excessive temperatures (hot or cold). On a bag of fertilizer, potash is the third number (0-0-X).

In September, fertilize Bermuda, zoysia and centipede with 1 pound of potash (K2O) per 1,000 square feet. There are three products on the market which can supply potash without supplying nitrogen. To get the correct rate, you can use 1.6 pounds of muriate of potash (0-0-60), 2 pounds of potassium sulfate (0-0-50), or 5 pounds of sul-po-mag (0-0-22). To determine the amount of product required to apply 1 pound of potash per 1,000 square feet, divide 100 by the third number in the fertilizer ratio. For example, for a 6-6-12 fertilizer, divide 100 by 12. The result is 8.3 pounds of product per thousand square feet.

Incorrect fertilization timing and rates can cause problems for any grass. Excessive fertilization can also have negative impacts on our natural environment.

Your grass gets hit hard by drought, bugs, heat, cold and other forces of nature. As you fertilize your lawn, simply tell your grass “Keep your head down. You can do it Rocky.”

For lawn maintenance calendars, visit http://www.ces.ncsu.edu/depts/hort/consumer/hortinternet/lawn.html If you don’t have internet access, then call the Extension Office at 893-7533 or email me at gary_pierce@ncsu.edu

Gary L. Pierce

Horticulture Extension Agent

Harnett County