Learning Activity: Grasscycling

Grasscycling

Grasscycling is the natural recycling of grass by leaving grass clippings on the lawn when mowing. Once on the ground, the clippings, which contain 80-85% water, decompose quickly returning valuable nutrients like nitrogen back into the soil. Grasscycling should be used as one piece of an integral lawn management system which also includes thatching, aerating, cutting, watering and fertilising.

LEARNING GOALS

Through the grasscycling exercise students can:

  • Understand the concept of grasscycling and its environmental benefits.
  • Explore how grass clippings can be used as a natural fertiliser to improve soil health.
  • Promote sustainable lawn care practices that reduce waste and enhance biodiversity.
  • Encourage critical thinking about waste reduction and eco-friendly gardening methods.

BACKGROUND INFORMATION

  • SUBJECTS: Science, Geography, Social Personal Health Education, Mathematics, Literacy 
  • IDEAL FOR: Schools with large grassy areas or sports fields, a Green School initiative in collaboration with caretaker/grounds person.
    • TIME REQUIRED:
      – Initial setup: 30 minutes (to explain the concept and prepare the lawn)
      – Activity: Ongoing throughout the year (after each lawn mowing session)
      – Follow-up discussion: 30 minutes per term to review progress and discuss environmental impact

    REQUIRED MATERIALS

    Grasscycling does not require the purchase of a special “mulching” or “recycling” lawn mower, although these do work better, especially in wet conditions or with tall grass. The most important thing is to keep the blades of your mower sharp – do this at the start of spring each year.

    Almost all mowers can be used or adapted to grasscycle, the main types:

    • Rotary mowers: remove the grass catching bag and cover the outlet spot (outlet covers are available from most manufacturers).
    • Special mulching blades designed to chop cuttings into tiny pieces and blow them into the lawn can be retrofitted to many mowers.
    • Reel-type mowers, including manual “push” mowers, can be used by simply removing the catcher.

    REQUIRED PRESMISES/EQUIPMENT

    • Lawn mower (ideally with a mulching feature)
    • Buckets or wheelbarrows to collect clippings (optional if the mower does not have a mulching feature)
    • Rake for spreading grass clippings evenly
    • Measuring stick or ruler to track lawn growth

    Preparation

    1. Choose a suitable lawn area in the school grounds where grasscycling will be implemented    
    3. Ensure the lawn mower is in good condition and set to the correct height (ideally 2.5 to 4 cm)    
    4. Inform students and staff about the project and its environmental benefits.
    5. Create a progress chart to track the benefits over time (e.g., reduced need for fertiliser, improved soil health)    

    In Class Tasks

    Step 1: Mow the Lawn

    • Mow the selected grassy area as usual    
    • If your lawn mower has a mulching feature, use it to finely chop the grass clippings    
    • If not, use a rake to spread the clippings evenly across the lawn    

    Step 2: Leave the Grass Clippings in Place

    • Instead of collecting the clippings, leave them on the lawn to decompose naturally    
    • Ensure the clippings are spread thinly and evenly to avoid clumping       

    Step 3: Monitor the Lawn

    • Over time, observe the health and growth of the lawn    
    • Track changes in soil quality and grass growth using a logbook or chart    

    Step 4: Discuss the Environmental Benefits

    • Hold regular discussions with students about the impact of grasscycling    
    • Encourage students to think about ways to reduce other types of garden waste

    TIP

    Don’t overwater the lawn!
    Grasscycling works best on a well-maintained lawn that isn’t overwatered. Overwatering can cause grass clippings to clump and slow down the decomposition process.

    A good experiment might be to divide an area in two. Practice grasscycling on one section and a conventional mowing regime on the other, and compare results over time in terms of how healthy the grass looks and how much time is spent cutting each section and how much time is needed to dispose of the grass cuttings from the conventionally mown section.

    The European Commission support for the production of this publication does not constitute an endorsement of the contents which reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein.
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