Most of the time, the best thing to do with grass clippings are simply leave them alone.
Grass clippings less than one inch in length filter down to the soil surface and decompose quickly while forming a nutrient-rich mulch.
It’s the longer clippings that tend to remain above the lawn, giving your yard an unsightly appearance and smothering the grass beneath. These clippings should be removed.
Optimum grass height varies by region – and by grass type.
Canada bluegrass won’t tolerate close cuttings and needs to be kept above 2-1/2 inches in order to survive.
Here are some general mowing guidelines for many of today’s most popular grass varieties:
RECOMMENDED MOWING HEIGHTS
|Grass||Cool Months||Warm Months||Final Mowing|
|Cool Season Canada bluegrass||3″||4″||3″|
Never remove more than a third of your grass height at one time.
Cutting your grass too short can severely limit its ability to manufacture food and resist weed invasions.
Grass that’s too tall can promote thatch build-up, encouraging insect and disease damage.
For best results, keep your lawn mowed to its optimum height.
IT VARIES BY SEASON
Mow frequently enough that only a small portion of the green leaf is lost at any one clipping.
Ideally 1″ a week so that no more than one-third of the leaf blade should be removed.
Cutting a lawn too often, particularly with the blade set low, exposes the lower portion of grass leaves to bright sun, burning them.
If this happens repeatedly, grass reacts by developing shallow roots.
Shallow-rooted lawns are particularly prone to disease and weed problems.
In addition, poor rooting does not provide enough nutrients to the grass leaves. A lawn with shallow roots may eventually die out.
Mowing frequency varies by the season.
In the spring, established lawns should be mown as soon as the grass greens and begins to grow.
In the summer, close mowing (especially during hot weather) can weaken some grass varieties.
As autumn approaches, cool-season grasses begin to grow faster and produce more clippings. Conversely, warm-season grasses begin to slow down.
Adjust your mowing habits accordingly.
PRIOR TO THE HEAT
Early evening is probably the best time to mow.
This gives grass blades time to recover before they’re exposed to daytime heat and wind.
Mow with a razor sharp blade, and never mow wet grass.
It’s actually best to mow your lawn in different directions.
That keeps grass from developing permanent ridges, ruts or becoming compacted from constant traffic.
Be sure that your clippings are thrown toward unmown grass when using a rotary mower as they’ll be chopped and pulverized better.
Thatch appears right at the soil surface and looks like a layer of straw.
It’s composed mainly of grass parts that live underground, but also includes lawn clippings and other un-decayed material.
In healthy soil, the plant parts decompose quickly into humus, but in soil that is compacted, over-watered, over fertilized or under populated with earthworms and soil insects, you end up with thatch.
Thatch causes a number of problems for your grass.
Thick thatch layers contribute to drought stress because water has a hard time reaching the soil and runs off instead of sinking in.
Numerous insect pests live and breed in the thatch layer. In humid climates, thatch harbors fungal diseases.
Light can’t easily penetrate thatch, making grass spindly.
The bottom line: a thick thatch layer is a sign of a sick lawn.
You’ll need a mower that has a dethatching attachment.
The large quantity of organic material brought to the surface from using a dethatcher should be removed from the lawn.
The best time to de-thatch is just before a lawn has its most vigorous growth of the season.
That means de-thatch warm-season grasses at the beginning of warm weather in late spring.
Conversely, the prime time for de-thatching cool-season grasses is late spring or early fall.
The actual frequency depends on the type of grass.
The best way to determine if your lawn needs to be de-thatch is to closely examine it.
If your lawn has more than 1/2 inch of thatch, you should consider removing it.