JoAnne Skelly: Grow a healthy, attractive lawn

For some gardeners, a green velvety expanse of lawn is their horticulture motivation. To achieve a healthy lawn, a gardener should know how to reduce thatch through core aerification, how to fertilize and mow properly and how to irrigate efficiently.

Thatch is a build-up of undecomposed plant matter between the soil and the blades of grass. Up to 1/2-inch of thatch is okay, but more prevents grasses from rooting into the soil. Thatch can result from shallow watering, improper fertilizing, soil compaction and damaging the microorganisms and earthworms that normally decompose the thatch. Core aerification is the best method to reduce thatch because it decreases compaction with the added benefit of improving water infiltration. An aerification machine penetrates the soil three to four inches deep and pulls up plugs of soil, thatch and grass. The cores stay on the lawn to put organic matter back into the soil. They can be mowed to chop them into smaller pieces. The optimal time to aerify is during cool weather in spring or fall.

Nitrogen is the most important nutrient for good turf development. Without adequate nitrogen, lawns look yellow-green and sparse. Nitrogen is the first number listed on a fertilizer label: N (nitrogen), P (phosphorus) and K (potassium).

After nitrogen, potassium is the next most important nutrient (for good root growth), followed by phosphorus (which Nevada soils usually have plenty of). Fertilize in six-week intervals from late April until early June, then don’t fertilize again until late August or early September, unless you use an organic or other slow release fertilizer. Follow the label directions for amounts and the right kind of spreader to use. Water the fertilizer in thoroughly after application. Avoid weed killer/fertilizer combination products. They contain little fertilizer and the weed killer can seriously damage or possibly kill trees, shrubs and other plants.

Water deeply, uniformly and infrequently to encourage deep roots. Adjust your irrigation timer to water according to the weather — less now, more as it heats up and the most in July (the hottest month), then back off as temperatures decline. Water when the top two inches of soil have dried out. Irrigate in the early morning.

Most grasses should be mowed to three inches high, removing only 1/3 of the leaf area at each mowing. This means you may have to mow more often rather than scalping long turf. Make sure lawn mower blades are sharp. Alternate mowing directions. Mow when the lawn is dry.

A healthy lawn is green, water efficient and weed-free.

JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at skellyj@unce.unr.edu.