How to Keep Grass Green and Achieve a Healthy Lawn
How to maintain a good-looking lawn with less time and effort
You Don’t Have to Slave Over Your Lawn to Keep it Healthy
If you’re an average homeowner (and of course you’re not!), you spend almost four hours a week on yard work and mow your lawn 30 times a year. And while you may not realize it, your lawn pays you back for all this hard work. It serves as a giant air conditioner to help cool your home. It releases a tremendous amount of oxygen and captures tons of dirt and dust to help keep you and your family healthy. It gives you a place to play croquet. (You’ll love these 12 backyard games, too!) And the healthier your lawn is, the better it keeps up its end of the bargain.
The good news is, you don’t have to slave over your lawn to keep it healthy. In fact, to a great extent, it’s not the amount of work you put into your lawn — it’s when and how you do it. The following six “ingredients” are essential for a healthy lawn. We focus on northern or cool-climate grasses like bluegrass and fescue, but most of the information applies to warm-climate grasses like zoysia and Bermuda grass, too.
Tip No. 1: Adjust your cutting height to the time of year.
The best height to cut grass depends on the type of grass, the region and the time of year. For cool-climate grasses, use a 1-1/2 in. cutting height for the first mowing of the year to remove dead grass and allow more sunlight to reach the crowns of the grass plants. Raise the blade during the heat of summer to two inches or more. Then lower the blade back to 1-1/2 in. for the last cutting of the year. For warm-climate grasses, these heights will be about 1/2 in. lower.
When adjusting your blade height, measure from a hard surface to the bottom of the mower deck, then add 1/4 in. Most blades sit 1/4 in. above the bottom of the deck.
Tip No. 2: Use a Sharp Mower Blade
A well-maintained, sharp and balanced blade cuts grass cleanly and evenly (see above). A dull one tears grass instead of cutting it cleanly. Damaged grass turns yellow, requires more water and nutrients to recover, and is more susceptible to disease. An unbalanced blade compounds the problem and can damage your lawn mower’s bearings. Sharpening and balancing a blade three times a year is usually enough to maintain a good cutting edge — unless you hit lots of rocks. Here’s how to sharpen a lawn mower blade.
Tip No. 3: A few good soakings are better than lots of light sprinklings
Deep watering helps develop deep roots that tap into subsurface water supplies (illustration below). Light sprinklings moisten only the grass and surface of the soil, encouraging shallow root growth and increasing the need for more frequent watering. Lawns generally require 1 to 2 in. of water per week from you or Mother Nature, applied at three- or four-day intervals. But this varies drastically depending on the temperature, type of grass and soil conditions. Lawns in sandy soils may need twice as much water since they drain quickly. Lawns in slow-draining clay soils may need only half as much.
When your lawn loses its bounce or resiliency, or when it wilts, exposing the dull green bottoms of the blades, it needs water. In general, water until the soil is moist four to five inches down, then wait to water again until the top one or two inches dries out. To find out how much water your sprinkler delivers, set out a cake pan, turn on your sprinkler, then time how long it takes for the water to reach a depth of one inch (see above).
The best time of day to water is early morning. Water pressure is high, less water is lost to evaporation and your lawn has plenty of time to dry out before nightfall. Lawns that remain wet overnight are more susceptible to disease caused by moisture-loving mold and other fungi.
Properly watered lawns develop deep, healthy roots. An impact sprinkler delivers water quickly, with less “hang time” for evaporation; a 3/4-in. hose delivers much more water volume than its 1/2-in. cousin.
Improperly watered lawns receive short daily waterings that promote shallow root growth. Oscillating sprinklers toss water in a high arc, so more evaporates before reaching the soil. Water your lawn better with these 10 easy tips.
Tip No. 4: Mow only the top one-third of the grass blade (and don’t rake up the clippings)
The top one-third of a blade of grass is thin and “leafy,” decomposes quickly when cut and can contribute up to one-third of the nitrogen your lawn needs (illustration below). While it’s decomposing, this light layer of clippings also helps slow water evaporation and keeps weeds from germinating. Check out these handy mowing tips.
But the bottom two-thirds of a blade of grass is tough, “stemmy” and slow to decompose, contributing to thatch. When thick enough, thatch prevents sunlight, air, water and nutrients from reaching the soil. Cutting more than the top third also shocks grass roots and exposes stems, which tend to burn in direct sunlight.
So if two inches is your target grass height, cut it when it reaches three inches. Since grass grows at different rates at different times of the year, “every Saturday” isn’t necessarily the best time to mow. Sometimes you need to mow it more, other times less. The ideal length for cool-climate grasses is three to four inches; for warm-climate, one to two inches.
Mow when the grass is dry and avoid mowing in the heat of the day when you’re more likely to stress the grass — and yourself.
Tip No. 5: With fertilizers and weed killers, timing is everything
When applying weed killers and fertilizers, take into account variables like geographic location, grass type, weed type and soil conditions. Here are a few general guidelines:
- A thick, healthy lawn (illustration below) that doesn’t provide weed seeds adequate sunlight or open space to germinate is your best defense against weeds. A sick, spotty lawn leaves lots of open space for weeds to take root and grow.
- Attack weeds in the early spring and summer before they have a chance to develop deep root systems, go to seed or reproduce.
- Different weeds require different chemicals and methods. It’s best to eradicate grassy weeds like crabgrass with pre-emergent weed killers, which destroy germinating plants as they sprout. Broadleaf weeds need to be attacked while they’re young and actively growing; spraying the leaves of individual plants or patches of plants is most effective. Dandelion killers work by literally growing the plant to death.
- Fertilize in early spring to jump-start root development. Fall feedings help repair summer damage and spur the root growth that goes on for several weeks even after the top growth stops, helping grass survive the winter. Light feedings in between help maintain healthy growth.
- Read the package. Some chemicals work only in the presence of moisture; other chemicals are rendered useless by water. Heed the safety warnings too.
The best resource for identifying and troubleshooting weeds is a nursery or garden center familiar with local conditions.
Tip No. 6: Aerate your lawn to help it ‘breathe’
Grass roots need oxygen as well as water and nutrients. Aerating — the process of removing small plugs of soil (see illustration) — produces multiple benefits. It improves air-to-soil interaction. It allows water and fertilizer to penetrate the soil deeper and easier. It reduces soil compaction and opens space for roots to grow. It removes some thatch and stimulates the breakdown of the remaining thatch. The best tool for this task is a gas-powered aerator, available at most rental centers.
Again, timing is critical. You can aerate in the spring. But fall, after the kids are through trampling the grass and there are fewer weed seeds to set up home in the open spaces, is the optimal time to aerate. It’s usually best to aerate first, then apply any weed killers so the open holes are protected against weeds.
A well-aerated lawn provides space for grass roots to grow, reproduce and take in more oxygen, moisture and nutrients. The plugs, composed of thatch and soil, quickly break apart and decompose. The roots of a compacted lawn have difficulty absorbing air, water and nutrients.
What’s next? Landscaping
Now that you have a beautiful lawn, check out these tips for landscaping your backyard.