After some pretty cold temperatures and snowstorms this winter, people are already thinking about spring and getting outside. Maybe your lawn did not perform as well as you would have liked last year. Your plan is to get out there early with the fertilizer and get on the right track for beautiful green grass this summer. Read along to be sure your plan is a fit with your type of grass, and be sure your time, money and efforts are spent wisely.
Most people in the Sandhills have a warm season turfgrass. It may be zoysia grass, Bermuda grass, or centipede grass. All these grasses go dormant in the winter, then green up in the spring and grow vigorously throughout the summer. Not every warm season grass is treated the same, however. Centipede grass is very common in our area. It is easy care, requiring mowing only every two weeks or so, and little in the way of fertilizer. It even prefers a slightly lower soil pH (pH is a measure of soil acidity — which centipede prefers to be around 5.5 vs. 6.2 for zoysia and Bermuda grass). One sure fire way to mess up your centipede grass? Fertilize in the spring. Centipede is finicky about when and how much fertilizer is used. Fertilize with nitrogen just one time: at the end of May or first week of June, and then with only a half-pound of nitrogen per thousand square feet (other grasses need much more much nitrogen — more on that in a minute). When fertilizing, use a high potash, or potassium, fertilizer — something with a 1:1:3 or 1:0:3 ratio of nitrogen-phosphorous-potassium (N-P-K). Look for something like a 5-5-15 or 8-0-24 fertilizer blend, rather than the typical 10-10-10. If the centipede grass still isn’t green enough to suit you, try a July application of iron, which can help green up your grass without adding too much nitrogen.
Zoysia grass and Bermuda grass are more demanding turfgrasses that require more inputs and more frequent attention. Fertilize a few weeks after green up (usually in late April or early May), providing a half-pound of nitrogen per thousand square feet using a complete fertilizer, something with a 3-1-2 ratio such as 12-4-8. With zoysia grass, continue to fertilize every four to six weeks with the complete fertilizer, applying no more than a half-pound of nitrogen each time. Zoysia should not receive more than 2 pounds of nitrogen total per growing season. Mid-August should be the latest zoysia grass is fertilized with nitrogen for the year. For Bermuda grass, after the initial fertilization of a half-pound of nitrogen per thousand square feet, apply a pound of nitrogen with your complete fertilizer through August, and then with only a half- pound of nitrogen in September, with a fertilizer with a high potash (potassium) ratio. Both centipede grass and zoysia grass will benefit from a September application of potash alone using 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) per 1,000 square feet. Potash is an important nutrient that helps plants manage water uptake, resist drought, and improves winter hardiness. Our sandy soils are naturally very low in potash, so don’t skip this important step.
Weeds are one of the biggest challenges in lawn care. Late February and early March is the time to apply a pre-emergent herbicide for warm-season weeds such as crabgrass; apply a post-emergent herbicide in May (after green up) as necessary for clover, spurge, and other broadleaf weeds. Use a two- or three-way herbicide to improve control. Make sure the herbicide is labeled for zoysia and Bermuda, and follow label directions. Weed control in centipede is more challenging. Many common herbicides can damage centipede grass, such as 2,4-D and dicamba, so read labels carefully; often the rate for centipede is half that for Bermuda, so be sure you are following the recommended rate. Remember, the best way to control weeds is to have healthy grass, so fertilize, mow and water (about one to one and a half inches of water per week if no rain) to ensure optimal growth.
When was the last time you soil tested your lawn? Fall is the best time to do this task, as, if lime is needed, it takes four to six months for the lime to take effect. However, remember that if the soil pH is too low, plants are unable to affectively uptake fertilizer, and will not perform well.
For more information on managing your turfgrass, weed identification and more, contact the Richmond County Extension office at 123 Caroline St., Rockingham, or call 910-997-8255.
Paige Burns is assistant horticulture agent at the N.C. Cooperative Extension’s Richmond County office.