May Gardening Tasks

Caring for warm-season grasses

The first week of April was rainy and then sunny skies for the rest of the month with very warm temperatures. The National Weather Service 3-4 week forecast for May suggest that rainfall will be above normal. (Check here). So hopefully we will get some relief. Otherwise, be sure to keep irrigation systems running especially on new plantings and anywhere fertilizer is applied.

Lawns: All of the different warm-season turf grasses have a pH and fertilizer preference. Turf grass should be actively growing before fertilizing so wait until you have had to mow your lawn a couple of times before making a fertilizer application. For the most accurate fertilizer recommendations a soil sample should be submitted to Clemson’s Agricultural Services Laboratory. You can either take your sample to your county Extension office, bring it by the nursery or mail it directly to the lab. Specific fertilizer recommendations will be in the results as well as liming recommendations.

For more information on taking a soil sample please visit:
https://hgic.clemson.edu/factsheet/soil-testing/

If you don’t soil test, use a complete fertilizer such as a 16-4-8 or 12-4-8 formulation for Bermuda, zoysia or St. Augustine. For centipede lawns a better choice is a 15-0-15 formulation, since this grass is not tolerant of high phosphorous levels. For the sandy soils of the coastal area slow-release fertilizers work best. Clemson recommends that most of the turfgrasses receive 1 to 4 pounds of actual nitrogen per 1,000 square feet applied during the growing season. Centipede and carpet grass are the exceptions; recommendations are for 1/2 to 2 pounds of actual nitrogen. Too much nitrogen on centipede may lead to disease issues. Split applications work well so apply half of the recommendation now and the rest in late summer. Be sure to water in the fertilizer.

For formulas to calculate actual needed amounts of fertilizer please visit:
https://hgic.clemson.edu/factsheet/fertilizing-lawns/

Each different turf type has an ideal mowing height also. For Bermuda, centipede, and zoysia the height is approximately 1-2 inches; for St. Augustine 2-4 inches is recommended. In shade or during drought, all grasses should be allowed to grow higher. In general, never cut more than a third of the leaf blade at a time. If you cut too much at one time your lawn is likely to look brown as you have removed all of the green tissue. For those of you wanting more of a putting green, bear in mind that your lawn will need higher maintenance not just in more frequent mowing but also more water and fertilizer. Such conditions may increase the possibility of disease issues so be sure to water early in the day and do not over fertilize. Clemson’s HGIC website has maintenance calendars for all of the warm season grasses, so for more information please visit: https://hgic.clemson.edu/ and do a search for your specific turfgrass.