What is Grasscycling

Grasscycling is simply leaving the grass clippings on the lawn rather than bagging them up. Since grass clippings are high in nitrogen, it can provide up to 50% of the fertilizer needs of a typical lawn. Grass clippings are 80 to 85% water and will typically decompose in 7 to 14 days and leave behind nutrients for the lawn.

Grass clippings will not cause excessive thatch build-up. Thatch is the accumulation of dead roots and stems and is most often caused by over fertilizing and over watering.

How Grasscycling Helps

Grass clippings left on the lawn provide for the following:

  • Return valuable nutrients to the lawn
  • Create an irrigation effect because of the water in the clippings
  • Reduces water evaporation from the lawn
  • Enhances lawn tolerance to drought
  • Facilitates better growth of the lawn
  • Keeps the soil temperature cooler
  • Eliminates materials going to the landfill.
Tips for Grasscycling
  • Mow when conditions are dry
  • Keep mower blade sharp – sharpen the blade 3 or more times during the season – sharp blades cut cleaner and disperses grass better
  • Don’t let large clumps of grass clippings accumulate on the lawn
  • Never cut more than the top third of grass each time you mow – cutting more of the grass stresses the roots
  • Water the lawn less frequently, but for longer periods of time – excessive watering can lead to thatch problems
  • Mow every 7 days during the spring and summer
  • Apply slow-release fertilizers in the spring and fall for steady growth – fertilizing in the summer is not really helpful to the grass and creates more work
  • Water only in the morning to reduce evaporation from the heat of the sun – up to 60% of the water evaporates when watering during the heat of the day
  • Avoid overuse of harsh chemicals and fertilizers – excessive fertilizing can lead to thatch problems
Fertilizing and Watering Practices

It is important to know the proper applications of fertilizers and water on the lawn. More is not better for either of these. Too much fertilizer can cause thatch, cause grass to grow faster and create more clippings. Too much water and water too often can drown the roots of the grass. Watering less frequent, but more intense will cause the roots to grow deeper into the soil which will make the grass stronger and more tolerant to drought. Water frequently will cause shallow root growth and make the grass susceptible to drought conditions and a weaker root system.


Apply fertilizers to the lawn in late April and again in September. Generally, apply approximately ½ pound of nitrogen per 1000 square feet of lawn. To determine application rate, find out the nitrogen (N) percentage in the bag and double that number and then divide it into 100. For example:

Fertilizer N-P-K %
Divide 100 by twice the % of Nitrogen (N)
Pounds of fertilizer to use per 1000 square feet
100 divided by 24
4.1 lbs.
100 divided by 32
3.1 lbs.
100 divided by 40
2.5 lbs.
100 divided by 20
5.0 lbs.


Fertilizers with slow-release nitrogen provide for a slower and more uniform growth. Examples include methylene urea, urea-formaldehyde, sulfur coated urea, or IBDU. The bag of fertilizer may also read “slow release nitrogen” or “water insoluble nitrogen.”


Follow these rules on watering the lawn:

  • Water only when the grass really need it – conserve water!
  • Water at 1-inch applications – One inch of water is adequate to wet the soil to a depth of 4” to 6”. To determine this, place an empty tuna can in the lawn near the sprinkler. Mark in the can a line measuring one inch in depth. Stop watering when the depth of the water in the can reaches that line. If water begins to run off the lawn prior to that point, turn off the sprinkler for an hour to allow and then resume watering until 1” is applied.
  • Water deeply and infrequently – light frequent watering encourages shallow root growth and leads to thatch and an increase in grass disease
  • Water in the morning – temperature is cooler and there is less evaporation. Watering at night can lead to the growth of fungus and disease.