Time to aerate the grass

tree shadow on turfgrass
Aerating in the spring helps lawns produce new growth. Photo by Wendy Hanson Mazet, Cooperative Extension.

Driving around town, it’s obvious that spring is here. Although you might be noticing that some lawns are dark green, others still have patches with shades of straw color. Yes, it is the season of flowers, but it is also time to take care of your lawn.

If your lawn doesn’t look as though it is vigorously growing and green, or if you’ve had issues with it in the past, it’s time to give it a fresh start. The majority of grasses grown in northern Nevada are considered cool season grasses. The most popular cool season grass is a Kentucky Bluegrass/fine fescue blend. It provides that lush, dark green, soft appearance that everyone loves to walk across in their bare feet. However, in order to have that beautiful lawn, you need do some work to keep the lawn healthy.

If you walk across your lawn and it feels like you’re walking across a thick carpet or it feels like you are walking on top of a sponge, you probably have a problem with thatch. Thatch is a layer of dead and living grass stems and roots that builds up between the soil and the grass blades in your lawn. Thatch build-up starts when the lawn produces organic debris faster than it can be broken down. It typically accumulates as a result of improper watering and excessive fertilization.

Or, you may have the opposite situation, when you walk across your lawn and it feels like you’re walking on concrete. This is a sign of compaction, which can happen from daily use, mowing or improper installation.

One of the best things to do in the spring to combat thatch is to aerate your lawn. Aerating helps with removal of accumulated thatch and reduces compaction issues. By physically pulling cores of soil, thatch, and grass out of the ground, you create air pockets. These pockets allow moisture to penetrate through compacted surfaces and through the thatch layer. It also gives the grass roots an opportunity to get much-needed moisture and oxygen, stimulating new roots.

One of the hardest things for most homeowners to do is to leave the plugs on the lawn. Yes, it looks like your lawn is covered with debris, but it’s very important to leave it on for at least one week. In each plug that is pulled out are microorganisms, including beneficial fungi. If you have thatch problems, the microbes in the plugs will eat away the thatch layer.

Normally, after a week of watering the lawn, the beneficial microbes within the plugs will be rinsed into the top of the thatch layer. Aeration of the lawn should be done twice a year, in spring and fall, when the grass is growing in the ideal cool temperatures, naturally producing new growth above and in the root system.

Wendy Hanson Mazet is a horticulture plant diagnostician for University of Nevada Cooperative Extension in Washoe County. If you have further questions on how to care for your lawn, contact the Master Gardeners at mastergardeners@unce.unr.edu or 775-336-0265.