The Benefits of Grass Clippings as Mulch
Weed Suppression: Grass clippings act as a natural barrier on the soil’s surface, limiting the exposure of weed seeds to sunlight and thereby inhibiting their germination. This leads to a significant reduction in the number of weeds competing with your garden plants for nutrients and water.
Moisture Retention: A layer of grass clippings can help the soil retain moisture, reducing the frequency of watering needed. This layer slows the evaporation of water from the soil, maintaining a consistent level of moisture which is particularly beneficial during dry spells and hot weather.
Organic Matter Enrichment: As grass clippings decompose, they contribute to the soil’s organic matter content. Increased organic matter improves soil structure, promotes beneficial microbial activity, and enhances the soil’s water-holding capacity and nutrient availability.
Soil Fertility Boost: Decomposing grass clippings release valuable nutrients back into the soil, acting as a slow-release fertilizer. This enriches the soil and provides a steady supply of nutrients to support plant growth without the immediate need for additional chemical fertilizers.
Essential Cautions before Mulching
Avoid Herbicide-Treated Clippings: I don’t use any chemicals on my land, but it is worth saying that gardeners should never use grass clippings from lawns that have been treated with herbicides. These chemicals can persist in the clippings and potentially damage or kill garden plants.
Handle with Care Around Young Plants: Fresh grass clippings can generate heat as they decompose. I tend to apply them as mulch to established plants rather than my new young plants. They can “burn” sensitive young plants if they are applied too thickly. The other option is to apply thin layers and reapply frequently.
Apply thinly. If grass clippings are applied as a thick mulch they can end up becoming a slimy, sludgy mat, which will attract slugs. Not ideal for your plants. I apply grass clippings thinly to avoid this.
Gathering and Applying Grass Clippings
To collect grass clippings for mulching, you may use a mower fitted with a bagger attachment to efficiently capture the clippings as you mow. Alternatively, if a bagger is not available, wait for the grass to dry and then rake the clippings into windrows. Either method will provide you with the needed material for mulching.
Spread a thin layer over moist soil ensuring that the clippings are not clumped together; this fosters proper air circulation and prevents matting. Press the mulch down to secure it, creating a blanket that keeps weeds at bay and locks in soil moisture.
Addressing the Drawbacks
Periodic Re-Application: Grass clippings break down over time, which necessitates adding more layers to continue weed suppression and soil moisture retention. Gardeners should monitor mulch thickness, topping up when it thins out. I find that I tend to reapply every one to two months, but it does depend on rainfall and temperature.
Nutrient Depletion from the Lawn: Regularly removing grass clippings for mulch can strip nutrients from your lawn. I want a healthy lawn as much as healthy plants in my veg beds. The approach I take is to use the grass clippings for two purposes;
- To mulch back into the lawn
- To mulch veg beds
This is a bit of a balance but it works best for me to mow and leave clippings to drop and mulch back into the lawn on every alternate mow. Then collect for mulch in the garden on the other mow. If I have surplus clippings at any point then I add these to the compost bin (mixed in layers with browns to balance out the nitrogen of the grass clippings).
Matching Mulch to Crops
Grass clippings prove valuable as mulch for specific crops, enhancing growth by retaining garden moisture and suppressing weeds. Courgettes, onions, peas and carrots particularly gain from this technique, as the mulch supports even soil temperatures and deters pests. For these crops, a layer of grass clippings can reduce the need for frequent watering and weeding, allowing them to flourish with fewer interventions.
Potatoes mulched too heavily with only grass clippings risk exposure, leading to greening and potential toxin accumulation.
Sustaining Your Green Space: A Recap on Mulching with Grass
Mulching with grass clippings can significantly enhance the health and productivity of your garden. These cuttings aid in suppressing unwelcome weeds and assist in retaining soil moisture, providing a dual benefit of weed control and water conservation. As they break down, grass clippings deposit valuable organic matter back into the soil, enhancing its fertility and structure. This cycle promotes sustainable gardening practices by repurposing a common garden waste material into a nutrient-rich resource for your garden beds.
Selecting the right mulch for the right crop can lead to a bountiful harvest. By recognizing the unique requirements of various plants, you can optimize your use of grass clippings, keeping your garden productive and sustainable.