Whether you have a faithful sidekick or not, it’s time for the “lawn ranger” to get busy. During these hot times when the grass is really growing, it’s important to saddle up that lawn mower often and keep the blades sharp. This month is also the right time to fertilize Bermuda, zoysia and St. Augustine if you’re following N.C. State University’s recommendations.
When it comes to mowing, remember the old rule-of-thumb of never removing more than a third of the leaf area at one time. For example, if you’re maintaining St. Augustine grass at 2 inches, mow whenever the grass reaches 3 inches tall. Buy an extra blade for your mower and have it sharp and ready when the other one loses its edge. You’ll know you need to change blades when the grass blades look ragged and torn rather than cleanly cut.
Take a cue from the golf course folks and mow your lawn in different directions to reduce wear patterns. This is especially important if you use a heavy riding mower. The golf course guys — in addition to reducing the wear and tear in one place — are looking for the pretty stripes as the mower pushes the grass blades in one direction or the other. You won’t get much of a stripe effect on most of our lawn grasses, but you will avoid the wear and the boredom of mowing the same way each time.
August is the right time to add nitrogen to keep your lawn green and healthy for the rest of the season.
St. Augustine and zoysia need about a half pound of actual nitrogen for each 1,000 square feet. Consider using a centipede fertilizer like 5-5-15 at 10 pounds per 1,000 square feet. It’s fairly easy to apply 10 pounds of material evenly. If you attempt to apply that same half pound of nitrogen with a fertilizer that’s 30 percent nitrogen, you’ll only need 1.67 pounds of material. Even though I’ve applied lots of fertilizer in my time, I can’t consistently apply that little bit of fertilizer evenly over those 1,000 square feet. Most of us end up applying too much and over-stimulating the grass.
Bermuda grasses — especially the hybrids — should receive one pound of actual nitrogen this month. 16-4-8 at about 6 or 7 pounds per 1,000 square feet works pretty well.
Whatever fertilizer analysis you choose, make sure a portion of the nitrogen is slow-release. The cheapest fertilizers will have nothing but quick-release nitrogen. When it’s warm and wet, your nitrogen will be used up or leached within two weeks.
Once you’ve applied the fertilizer, sweep or blow the granules from paved surfaces like sidewalks and driveways. Fertilizers with iron will leave rusty spots everywhere if not removed. And, all of that nitrogen and phosphorus needs to stay on the lawn rather than ending up in surface waters to stimulate algal blooms.
Trying to figure out which grass to plant can be a complicated question here in southeastern North Carolina. One of our projects this summer was to redo the turf demonstration plots at the Arboretum. You’ll find 10 different grasses including old favorites like centipede, Empire zoysia and St. Augustine as well as newer selections including Discovery Bermuda and Greg Norman zoysia.
If you need some one-on-one help, our Plant Clinic is open Monday through Friday between 10 am and 4 pm to help you solve garden problems at the New Hanover County Arboretum – 6206 Oleander Drive in Wilmington. Help us out by bringing representative samples of what’s going on. Photographs are often helpful for context. You can also check out our website ces.ncsu.edu where you can submit questions via the ‘Ask an Expert’ link, or contact your local Cooperative Extension center by phone: If you live in Pender County, call 910-259-1238; in New Hanover County, call 910-798-7660; in Brunswick County call 910-253-2610. You can also find great local information at nhcarboretum.com and on Facebook. Just search for “New Hanover County Arboretum.”
Al Hight is the extension director for the North Carolina Cooperative Extension in New Hanover County. Contact him at 910-798-7666.