What is Grasscycling?
Grasscycling is the natural recycling of grass by leaving clippings on the lawn when mowing. Grass clippings will quickly decompose, returning valuable nutrients to the soil.
Grasscycling saves time, money, and protects the environment. Mowing time is reduced since the bagging and disposal of clippings is eliminated. Grass clippings add beneficial organic matter to the soil, which provides free fertilizer and produces healthy, green lawns. Grasscycling reduces the need for turf grass fertilizer and water requirements, which can minimize toxic runoff entering storm drains and polluting lakes, creeks, and rivers.
Lawns can generate approximately 300 pounds of grass clippings per 1000 square feet annually. This can be as much as 6 1/2 tons per acre each year! Grass clippings are too valuable to throw away, and grasscycling allows this green material to be reused in our urban landscapes.
Many people treat their lawns like a “crop”: they over water and over fertilize their lawns to encourage excessive growth. The “harvested crop” (grass clippings) is then bagged and disposed. Proper mowing, watering, and fertilizing practices result in more moderate turf growth, yet still produce a healthy, green lawn. Grasscycling can be practiced on any healthy lawn as long as the following turf management guidelines are followed.
Turfgrasses vary in their need for water. Most grasses in California need about 1 inch of water every 5 to 7 days in the growing season and much less during slow growth months. Lawns watered too frequently tend to develop shallow root systems which may make them more susceptible to stress and disease. Deep, infrequent watering produces a deeper, extensive root system which enables turf to resist disease and stress. Over-watering is not only wasteful, it also causes lawns to grow faster and requires more mowing. The best time to water is early in the morning, as less water is lost due to evaporation. Try to avoid watering in the evening because prolonged damp conditions may encourage disease development.
Check your irrigation systems regularly to avoid water runoff and over-spraying, especially if the lawn is on a slope. Look for broken, tilted, or clogged sprinkler heads, and adjust to ensure even coverage. Remember to adjust your irrigation timer seasonally to match the water needs of the turf.
Proper fertilization is essential in maintaining a healthy lawn. However, over-fertilization can weaken a lawn by causing excessive and succulent top growth. For moderate, even growth, use a combination of fast acting fertilizers (ammonium nitrate, ammonium sulfate, or urea) and slow release nitrogen sources such as sulfur-coated urea, urea formaldehyde, IBDU or organic fertilizers. Avoid using large quantities of fast acting fertilizers. These fertilizers produce very fast growth for short periods.
Regardless of the grass type and its fertility needs, as a general rule, your lawn will be healthier with smaller quantities of fertilizer applied more frequently rather than larger amounts applied less frequently.
Proper mowing is required for successful grasscycling. It is best to cut grass when the surface is dry, and keep mower blades sharp (dull blades can shred grass and create a potential entryway for disease). Follow the “1/3 rule:” mow the lawn often enough so that no more than 1/3 of the length of the grass blade is removed in any one mowing. Proper mowing will produce short clippings that will not cover up the grass surface. You may have to cut the lawn more frequently, or double cut, when the lawn is growing fast, such as in the spring, but much less when the turf is growing slowly. Additionally, raising the mowing height in the summer encourages deeper roots and protects grass from drought and heat damage. Check out the chart below for recommended mowing heights.
Mower setting (inches)
Mow when grass is: (inches)
|Bentgrass||1/2 - 1||3/4 - 1 1/2|
|Bermuda Grass||1 - 1 1/2||1 1/2 - 2 1/4|
|Bermuda Grass||1/2 - 1||3/4 - 1 1/2|
|Kentucky Bluegrass||1 1/2 - 2 1/2||2 1/4 - 3 3/4|
|Kikuyugrass||1 - 1 1/2||1 1/2 - 2 1/4|
|Perennial Ryegrass||1 1/2 - 2 1/2||1 1/4 - 3 3/4|
|Tall Fescue||1 1/2 - 3||2 1/4 - 4 1/2|
|St. Augustine||1 - 2||1 1/2 - 3|
|Zoysia||1/2 - 1 1/2||3/4 - 2 1/4|
You can grasscycle with almost any mower. Refer to your owner’s manual or contact a lawn mower dealer to learn if you can safely grasscycle with your existing mower, or if you need to purchase a retrofit kit. Mulching or recycling mowers make grasscycling easy by cutting grass blades in to small pieces and forcing them into the soil. You may also want to consider purchasing an electric mulching mower to reduce air pollution.
Frequently Asked Questions
Does grasscycling cause thatch build-up?
No. Research has shown that grass roots are the primary cause of thatch, not grass clippings. Thatch is composed mainly of roots, stems, rhizomes, crowns, and stolons. These plant materials contain large amounts of lignin and decompose slowly. Grass clippings are approximately 80-85% water with only small amounts of lignin, and decompose rapidly. Some grasses such as bermudagrass and kikuyugrass are more thatch-prone than others.
A small amount of thatch (approximately 1/2 inch) is actually beneficial to a lawn, providing insulation to roots and serving as a mulch to prevent excessive water evaporation and soil compaction. It may also create a cushioning effect for lawn play.
Does grasscycling spread lawn disease?
No. Improper watering and fertilizing are the primary cause of disease spread. If an accommodating environment for turfgrass disease is present, infestation will occur whether clippings are collected or not.
Will grasscycling make my lawn look bad?
No. If a lawn is properly mowed, watered, and fertilized, grasscycling can actually produce a healthier-looking lawn. It is important to cut the lawn frequently to produce small clippings that will fall between the standing blades and decompose quickly. However, if a lawn is not cut frequently enough and long clippings are left on the lawn, it may produce a “hay-like” look which can be unsightly.
Are there alternatives to grasscycling?
Yes. Grasscycling is not feasible in every situation. Prolonged wet weather, mechanical breakdown of mowers, or infrequent mowing are situations where grass clippings should probably be raked up since an excessive volume of clippings may be generated. But do not throw the clippings away!
Grass clippings are an excellent addition to a backyard compost pile. Clippings can also be used as mulch to provide weed control and prevent moisture loss around flower beds, trees, and shrubs. Mulching with clippings should be avoided, however, if they are of an invasive variety, such as Bermuda grass, or if herbicides have been applied recently to the lawn.