Everything you need to know about eco-friendly lawn mowing

I actually enjoy mowing my lawn. We have a riding mower and a rather large piece of property so it's a very relaxing activity for me.

When we began trying to be more eco-friendly in our yard, I  had to make myself cut back on the number of times I mowed and raise the height of the blade. I just hadn't realized that things like that, as well as the sharpness of the mower blade, could make such a big difference in the health of the lawn…and the health of the planet. These actions even help you save water, because sharp mower blades result in less water loss from the grass. Taller grass also encourages a deeper, more extensive root system with increased drought tolerance, and  is also  more effective at shading out weeds in the landscape. And of course, healthier lawns require less chemicals to keep them looking good and green.

Depending on where you live in the Metro DC area and what grass you grow, you will probably mow your lawn 20-40 times a year. Here are some tips to make sure that you don’t do more harm than good when you are performing lawn maintenance:

1)    Get to know your grass – As with everything in your landscape, it’s best to get to know as much as you can about the species that you are dealing with so that you can make the right choices in taking care of it.  Whether you already have an established lawn or are putting in a new one, get to know your grass. Turfgrasses that provide winter lawn color in the area are known as cool-season grasses. Grasses which go dormant after the first hard frost, and stay brown through the winter months are known as warm-season grasses. Your choice of grass species will affect how you mow.  Selecting turfgrass , Turfgrass Species   <— Excellent information  with photos of grass species

2)    Set mowing heights according to grass species  - Once you know what species you have, you can set your mower blade at the recommended height for your species.(See Turfgrass Species link above and check on Planting and Maintenance Tips). While there are some differences in tolerable cutting heights between the various species of warm and cool-season turfgrasses, a general rule of thumb is to clip them in the 2-3 inch range. Mowing tall promotes a deeper root system and improves turf competitions against crabgrass and other warm-season weeds. If your lawn has a white hue rather than a green color after you mow, it is a good bet that you are cutting too low.

3)    Keep blades sharp and balanced – The quickest way to improve lawn quality AND turf health is to keep your mower blade sharpened. A sharp blade will also improve mower fuel efficiency and extend mower engine life.  Blades should be sharpened at least three times per growing season: start the year off with a sharp blade, sharpen it again in late spring, and then once more in mid-late summer.

4)    Adjust mowing height for different seasons– For cool-season grasses, another tip that promotes summer health and performance is to raise the cutting height during the summer.  A higher mowing height in summer helps to cool the crowns of the turfgrass plants and provides more leaf area for photosynthesis during the stressful summer months. Taller cutting heights at these times help maintain the plant’s root system. On the other hand, warm-season grasses respond to mowing on the lower side of their recommended range in the summer by increasing in density.  Whereas fescues and bluegrasses thrive at mowing heights of 2-3 inches during the fall and early spring, for summer the best strategy is to mow at a 3-4 inch height (or even taller).  Raise the cutting deck to its highest setting when it needs clipping and don’t feel compelled to get the mower out at all if the grass is not growing.

5)    Mowing new lawns –  New lawns need time for their roots to become established before they can be mowed for the first time. For seeded lawns, it may take up to 2 months before they are ready to be mowed. Sod may be ready to be mowed within 2 to 3 weeks of planting. Three to six weeks are required for sprigs, stolons, and plugs to become established. For seeded lawns, wait for all of the seeds to germinate before mowing. For sod, sprigs, stolons, and plugs, make sure the roots are firmly planted in the soil before mowing to avoid tearing out new turf.  Follow these tips for new lawns: Be sure that the lawn is fairly dry before mowing so that you do not pull out any of your new lawn. As a general rule, you should let your lawn grow to about one-and-a-half times the recommended height before cutting so that you are cutting off no more than one-third of the height of your lawn at a time. For the first mow, you can let the lawn grow to the high end of the recommended range or even a little higher before cutting to give it a little more time to become established, but be sure to still only cut off one-third of the blade.

6)    Adjust mowing height for shady spots – For shady areas,  mow on the high side of the recommended range in order to maximize the plant’s leaf area.  Your lawn grasses will already be at a huge competitive disadvantage to the trees in regards to light, water, and nutrients, so it needs some special attention to maintain a canopy.

7)    Employ the “1/3^rd rule” of mowing –  Lawn experts recommend that you shouldn’t remove more than 1/3^rd of the leaf blade when you mow.  Removing too much of the foliage while mowing shocks the plant, forcing it to redirect its food resources from roots and stems towards new leaves. That means that if you want to mow to a 3” height, you shouldn’t mow until your grass is 4.5” high. To mow to a 2” height, you would wait until the grass is 3” high.

8)    Mowing very tall grass–If the lawn has gotten away from you, resist the temptation to scalp it in a single mowing event.  Instead, slowly drop the mowing height every 2-3 days while returning the turf to its ideal height.  This will maintain plant health and prevent you from having unsightly piles of clippings that not only look bad, but can also smother the turfgrass and create an environment that favors disease development. Grass clippings should be bagged or raked and removed when mowing grass that has grown too tall.

9)    Change your mowing pattern – Alternate your mowing pattern or direction each time the lawn is mowed.   Repeatedly mowing the lawn in the same direction pushes the grass over rather than cutting it cleanly. Also, different mowing patterns reduce soil compaction and wear from the mower wheels.

10) Grasscycle – Finally, return clippings as often as possible to your turf. Clippings are nothing more than organic fertilizer for your lawn, and if you follow the 1/3^rd rule, you will never produce enough clippings to cause problems with your lawn.  You can reduce your turf’s fertility needs and help the environment by keeping your clippings in your lawn. NEVER blow your clippings into the street,where they can add to local stormwater pollution.

For More Information: Mow Like a Pro

Sources:  Virginia Cooperative Extension, University of California IPM