Extension

Oklahomans may have noticed their lawns are growing fast this summer. Keeping up with mowing may be a challenge, as is knowing what to do with grass clippings.

For the best results, don’t bag the clippings – instead, let them fall back into the lawn. Not only does this save time, but it also saves money. Without a collection bag attached, the mower is easier to push. Plus, there’s no need to stop to empty the clippings or to purchase disposal bags.

Homeowners want to do everything possible to care for their landscape. The grass clippings serve as a valuable source of organic matter and nutrients. Old-school thinking is that leaving clippings on the lawn causes thatch. In reality, thatch is a layer of undecomposed stems and roots that builds up between the soil surface and the growing turf. Grass clippings contribute very little to its formation.

Grass clippings are composed of about 85% water and contain 4% nitrogen, 1% phosphorus and 2% potassium, which makes them break down easily and return nutrients to the soil, encouraging new growth. Other ways grass clippings help include reducing erosion, increasing organic matter in the soil, suppressing weeds and conserving soil moisture.

During times of rapid growth, a lawn may require mowing more than once a week. Lawns maintained to the proper height are easier to mow. Waiting too long between mowings can remove too much of the grass blade at once, placing unnecessary stress on the turf.

The height of the mower deck depends on the type of grass being maintained. When the deck is set a little higher, it allows the clippings to settle back into the canopy more easily and protects the lawn during the summer heat. Taller grass produces deeper, stronger root systems, improving its ability to withstand high temperatures and other environmental stresses.

Mowing when the grass is dry will help evenly distribute the clippings. Also, sharp blades will reduce injury to the grass.

Homeowners who prefer to collect clippings should consider using them as mulch around shrubs, flowers, trees and vegetable gardens. However, avoid using clippings from lawns treated with herbicides within the previous two weeks, as residual weed-control products may damage desirable plants.

For those who compost, grass clippings are an excellent addition to a compost pile because of their high nitrogen content. It’s not a good idea to compost them alone since thick layers tend to mat together. This limits critical airflow needed for proper decomposition. Add only about 3 to 4 inches of clippings at a time and be sure to mix them with carbon-rich materials such as dried leaves or sawdust to maintain a healthy balance in the compost pile. Oklahoma State University offers more composting information online on HLA-6448 Backyard Composting in Oklahoma.

Grass clippings are a free and valuable resource that can improve soil health and contribute to a healthier landscape.