Lawn Mowing Mistakes — Part One

Mowing the lawn is one of the most common landscaping chores. Properly caring for your lawn involves a bit more than just pulling your lawn mower out once a week and running it across your yard. There are a few common mistakes you will want to avoid in order to have a healthy and beautiful lawn. Better Homes and Gardens authors and I offer a few tips to assist you in this area. Read on to discover the first two of these in Part One of this two-part series.   

First, you may tend to cut your grass too short. While it may seem like mowing the lawn shorter would enable you to engage in this task (for some enjoyable, for others detestable) less frequently, this can do more harm than good. Each blade of grass is part of a plant that gets its nutrients partially from photosynthesis. Mowing the yard too close reduces the leaf surface available to facilitate this critical plant function, resulting in a patchy lawn, damaging or even killing your grass. Short grass also makes it easier for weeds to move in and take over.

Instead of mowing the lawn super short (scalping it), keep your lawn mower blade relatively high and mow frequently. As a rule of thumb, you should never remove more than about one-third of a blade of grass in a single mowing. If your grass has gotten taller than usual, mow as high as you can, then a few days later, mow the yard again a little bit lower. Grass clippings should always be less than one inch long.

How short you mow your lawn also depends on the season. Yards can be cut a little lower in the spring and fall when the weather is cooler. In summer, keeping the height taller allows the blades to shade their roots and provides an extra leaf surface to fuel them.

Experts have raised their recommendations in recent years for mowing heights between 2 and 3.5 inches, depending on the type of grass. Cool season grasses such as Kentucky bluegrass, tall fescue, and perennial ryegrass—can generally be cut to 2.5 to 3.5 inches. Warm-season grasses that grow horizontally—such as centipede, zoysia, and Bermuda—can be mowed down to 2 to 2.5 inches.

Number two on the list of lawn mowing mistakes to avoid has to do with whether or not you collect your lawn clippings. Removing grass clippings while mowing the lawn with a bagging lawn mower is tempting, but doing so will rob your lawn of valuable nutrients. Grass blades are primarily composed of water (about 85%) and include many other beneficial nutrients, such as nitrogen, so they break down quickly and add these nutrients back to the soil, allowing you to use less fertilizer. If you already have a bagging lawn mower, you don’t need to buy a new one—you can remove the attachment on most models.

A common misconception is that grass clippings cause thatch, a layer of partially decomposed grass roots and stems that can build up between the soil surface and the growing grass. However, if your clippings stay under one inch long, they won’t cause this problem. However, if your lawn already has thatch that’s more than one-half inch thick, grass clippings can contribute to the problem. There are other solutions to the thatch problem, namely aeration. 

To prevent grass clippings from making a mess, keep them away from hard surfaces such as streets and driveways when mowing the lawn. If they’re sitting on concrete or another hard surface, they can be swept into storm drains, clogging them and affecting water quality down the line. Grass clippings contain phosphorus, a nutrient that turns lakes green with algae, and chemically treated decomposed clippings can also pose a threat to fish and other wildlife.

I hope these pointers will be helpful to you as you strive to have the healthiest and prettiest lawn around. Stay tuned for Part Two.

Tim Lewis is a Georgia Green Industry Association Certified Plant Professional, gardening writer, former Perry High School horticulture instructor, and former horticulturalist at Henderson Village and Houston Springs. He and his wife, Susan, own and operate Lewis Farms Nursery located on Hwy 26 two miles east of Elko, where he was born and raised. He can be reached at (478) 954-1507 and timlewis1@windstream.net.