A centipede grass fertilizer schedule looks very different from the one on the back of most fertilizer bags. Centipede is often called the lazy man's grass, and for good reason. It wants less nitrogen than any other common lawn grass in the Lowcountry, it prefers acidic soil, and it gets into real trouble when it is overfed. Many centipede lawns in Summerville, Goose Creek, James Island and across the Charleston area look thin and patchy not because they are starving, but because they have been given too much. This guide follows Clemson Cooperative Extension's recommendations for coastal South Carolina.
Why centipede needs less fertilizer
Clemson recommends no more than 1 to 2 pounds of actual nitrogen per 1,000 square feet per year for centipede. Some well established lawns do fine on less. Compare that to bermuda, which can take 3 to 5 pounds.
When centipede gets more nitrogen than it can use, it grows fast and lush, builds up thatch, and its growing points get lifted up away from the soil. Those exposed stems are more vulnerable to cold snaps and drought. Over a few years, that leads to a problem Clemson calls centipede decline. Large patches of the lawn fail to green up in spring, or green up and then die in late spring and summer. The damage tends to come back and spread each year.
So the rule for centipede is simple. Feed it lightly, feed it at the right time, and do not try to push it to be as dark green as St. Augustine.
Centipede grass fertilizer schedule for coastal South Carolina
This schedule is based on Clemson's centipede maintenance calendar, adjusted for the coast.
| Timing | Fertilizer step |
|---|---|
| January to March | No nitrogen. Take a soil test. |
| April | Lawn greens up. Hold off on nitrogen until green up is complete. |
| Early May | Half a pound to 1 pound of actual nitrogen per 1,000 sq ft. |
| June to July | Iron only if the lawn looks yellow. No extra nitrogen needed for most lawns. |
| Late summer, before about September 1 | Half a pound to 1 pound of actual nitrogen per 1,000 sq ft, using a high potassium product like 15-0-15. |
| September to October | No nitrogen. Potassium 4 to 6 weeks before first frost if the soil test calls for it. |
| November to December | No fertilizer. |
Use the higher end of each range on very sandy soil and the lower end on heavier soil. Keep the yearly total at or under 2 pounds of actual nitrogen.
Early May: the first feeding
Clemson recommends waiting until the lawn has fully greened up and is growing, which on the coast is typically late April into May. A frost after an early feeding can damage the tender new growth. Early feeding also helps winter weeds more than it helps the grass.
Late summer: the second feeding
The second feeding supports the lawn through the rest of the season. A fertilizer high in potassium, like 15-0-15, is a good choice because potassium helps with heat, disease and cold tolerance. On the coast, Clemson places this feeding before about September 1. Later nitrogen keeps the grass growing into fall when it should be hardening off.
Fall potassium
If a soil test shows low potassium, Clemson suggests about 1 pound of potash per 1,000 square feet about 4 to 6 weeks before the first expected frost, using a potassium only product such as muriate of potash or potassium sulfate. Do not add nitrogen in fall.
Phosphorus, pH and iron
Skip phosphorus unless a soil test says otherwise
Clemson advises applying phosphorus to centipede only if a soil test shows it is low. High phosphorus can make it harder for centipede to take up iron, and extra phosphorus washing off lawns ends up in ponds and marshes. Look for a fertilizer with a middle number of zero or close to it.
Keep the soil acidic
Centipede does best at a soil pH of about 5.5 to 6.0. Above that, it often turns yellow because it cannot take up iron well. Do not add lime to a centipede lawn unless a soil test calls for it. Lime raises pH, which is usually the opposite of what centipede wants.
Iron for color
When centipede turns yellow in summer, the fix is often iron, not more nitrogen. Iron greens the lawn without pushing extra growth. Liquid iron products and fertilizers with added iron are both options. Follow the label rate, and keep iron off concrete and pavers because it stains.
Other care that supports the schedule
Fertilizer is only one part of keeping centipede healthy.
- Mow at 1.5 to 2 inches. Clemson suggests about 2 inches in partial shade. Scalping hurts centipede's shallow roots. Our guide to mowing height for warm season grass has details.
- Water deeply and only when needed. Clemson recommends about three quarters of an inch to 1 inch of water when the lawn shows stress, such as a bluish color or footprints that stay in the grass. Frequent light watering keeps roots shallow.
- Manage thatch. Overfeeding and overwatering build thatch, which feeds the decline cycle.
- Watch for nematodes and ground pearls. Clemson notes centipede is highly susceptible to both. If a lawn keeps thinning despite good care, a nematode test through Clemson Extension can help rule it in or out.
- Be careful with herbicides. Centipede is sensitive to some common broadleaf weed killers, including 2,4-D. Always check that a product is labeled for centipede and follow the label closely. For weeds like dollarweed that love wet centipede lawns, see how to get rid of dollarweed.
Large patch in fall
Centipede is prone to large patch, a fungal disease that shows up as circular yellow and brown areas when soil temperatures cool in fall and warm in spring. Too much nitrogen, especially late in the season, makes it worse. Clemson notes that preventive fungicide in fall, as soil cools to around 70 degrees, can help in lawns with a history of the disease.
Right Stuff Lawn Care treats centipede as its own program for exactly these reasons. A schedule built for St. Augustine or bermuda will overfeed it. For the bigger picture on timing across grass types, read our guide to the best time to fertilize a lawn in Charleston SC.
Frequently asked questions
How many times a year should I fertilize centipede grass?
Usually twice. Clemson's calendar calls for a feeding in early May after green up and a second in late summer, before about September 1 on the coast. The yearly total should stay at or under 2 pounds of actual nitrogen per 1,000 square feet.
Why is my centipede grass turning yellow?
The most common cause is high soil pH, which keeps centipede from taking up iron. Too much phosphorus can add to the problem. A soil test will tell you, and an iron product usually restores color without extra nitrogen.
Should I put lime on centipede grass?
Only if a soil test calls for it. Centipede likes acidic soil around 5.5 to 6.0, and lime raises pH. Adding lime without a test can cause the yellowing people are trying to fix.
What is centipede decline?
It is the gradual dying out of centipede in patches, often seen when lawns fail to green up in spring. Clemson links it mainly to overfeeding, thatch buildup and poor watering. Light feeding, proper mowing height and deep, infrequent watering are the best prevention.