It is that time of year when I get a lot of questions about lawns. Homeowners want a great looking lawn and in order to accomplish this factors such as proper fertilization, mowing height, disease control and irrigation practices need to be considered.

Fertilization

On warm-season turfgrass species, withhold the first spring nitrogen application until soil temperatures at the 4-inch depth are consistently 65° F. I receive questions all the time about applying fertilizer early in the year especially when we have a warm February. Soil temperature data can to obtained by www.georgiaweather.net. This past week (Week of April 20) the soil temperatures have been in the low 60s.

Phosphorous and lime applications should be based on soil test results. A common mistake is to fertilize centipedegrass too early in the spring. Also, it is not uncommon for centipedegrass to be over-fertilized. One pound of nitrogen per 1,000 square feet per year is ample nitrogen for most established centipedegrass lawns.  

Mowing height

Mow turf grasses often enough so that not more than 30 percent (1/3) of the leaf blade is removed in a single mowing. If more plant material is removed, the grass can become stressed and more susceptible to disease-causing organisms and insects.

Keep mower blades sharp. Dull blades will shred the leaf tips, causing the turf grass to use more water, undergo undue stress and have a ragged appearance. Raise the mowing height during stress periods such as drought.

According to Dr. Clint Waltz, UGA turf specialist, bermudagrass and zoysiagrass needs to have a mowing height of 1 inch. If you have a centipede lawn, then maintain a mowing height of 1.5 inches. St. Augustine needs to have a 2.0 inch mowing height.

Disease control

Large patch has been diagnosed in a few samples sent to the diagnostic lab from local lawns in Moultrie. Rhizoctonia large patch is the most common and severe disease of warm season grasses (bermudagrass, centipedegrass, seashore paspalum, St. Augustinegrass, and zoysiagrass) across the state of Georgia. Due to spring and fall disease-promoting environmental conditions across Georgia coinciding with grasses leaving and/or entering dormancy, large patch can appear in warm season grasses in various grass-growing settings, including home lawns, landscapes, sports fields, golf courses, and sod farms.  

Irrigation

Apply water when signs of moisture stress (e.g., wilt) are observed on 30 to 50 percent of the lawn. Apply enough water to wet the soil 6 to 8 inches deep. This is usually equivalent to 1 inch of water or 600 gallons of water per 1,000 square feet.

To avoid runoff, the amount of water that can be applied in any single irrigation can vary with different soils. For example, the same amount of water will penetrate deeper into a sandy soil than a clay soil. If the soil becomes compacted, loosen it through cultivation such as core aeration. This will help the water penetrate the soil.

Irrigate during dry periods in early spring and late fall. Late afternoon irrigating can encourage disease development. Watering after dew development (approximately 9 p.m.) and before sunrise (approximately 6:30 a.m.) is most efficient and will not increase disease problems.