Proper mowing of your lawn can kill weeds and chinch bugs, cure disease, save water and provide fertilizer. However, improper mowing can be harmful. Mowing is stressful to grass because it is meant to grow tall, mature and make seeds. Man decided that lawns look good when freshly mowed and most people feel the shorter the better. But a close cut doesn’t do much for your lawn or your water bill.
Grasses are basal-growing plants. The growing point is at the crown (the area between the root and the blade) of the plant near the soil line. The tips are the oldest part of the blade which means you can cut off their tops without killing them. When you cut the tips, new growth pushes up from the crown. When the mower cuts off those grass tips, it causes severe shock to the grass plant.
Grass lives primarily on food manufactured in its blades not on what is drawn up through the roots. Cutting the blades reduces the ability of the plant to manufacture food. That food is used for both top and root growth so the shorter you cut the grass the less root growth you will have. A plant with deep roots will be better able to withstand drought, fight off disease and insects and store food manufactured in the leaves. So the longer the root the healthier the grass. Every time the grass is cut the root system is weakened to some degree. When cut too severely, the roots stop growing. Mowing tears the plant and creates ports of entry for disease. Sharp mower blades give a cleaner cut which heals faster. Another problem with close cutting is that it allows sunlight to dry the soil and the additional light will encourage weed seeds to germinate.
Mowing has actually tamed the wild grasses of our past. Mowing grass before it sets seeds prevents sexual reproduction and many grasses respond by reproducing asexually by spreading stolons and rhizomes creating a thicker lawn. How high you mow will also influence the spread of the grass. A higher cut makes healthier grass with deeper roots, more mass for photosynthesis and more stolons and rhizomes for a thicker sod which means less weed invasion.
You should also take into account that grass grows at different rates throughout the seasons. The summer months require more frequent mowing than our cold winter and dry spring months when you should not cut as often. Our coming cold weather will slow the growth and bi-weekly mowing will be all that is needed. Some lawns could go three weeks or a month without mowing. If the grass doesn’t need to be mowed save it from the extra stress and don’t mow it.
In past years drought required the city to reduce our allowed watering to once a week. The fact is our lawns could easily survive on this schedule and be healthier for it. We should practice horticultural practices every day which produce deep-rooted lawns that don’t require excessive water to keep them green. All lawns, properly cared for, could be conditioned to require no more than once a week watering all year. The exception would be during the cold winter months when once every two or three weeks will do.
Check your irrigation system to be sure of proper coverage. It may seem that the sprinklers are reaching all areas but if you have dry spots on the edge of your sprinkler pattern you may not be getting adequate water at the edges of the sprinkler pattern. Place some empty tuna cans at the center of the green areas and also in the dry areas and measure the water levels after the zone has run. You’ll most likely find you’re not getting enough in the dry areas.
A lush, green lawn is a beautiful thing. It doesn’t need excessive chemical and water use to look that way if you just raise the mower deck as high as it will go. A deeper lawn is a healthy lawn.
Eileen Ward and her husband Peter have owned and operated Greensward of Marco, Inc., a lawn maintenance and landscaping company, since 1981.