Can I Put Grass Clippings in My Vegetable Garden?

Growing a vegetable garden is such a rewarding activity, but sometimes the associated costs can seem prohibitive. If your wallet is looking thin after buying seedlings, soil, and other gardening supplies at your local home improvement store, here is some good news!

One of the best mulches for your vegetable garden is easily accessible, and free! Grass clippings from your own lawn can be an excellent source for mulch in your vegetable garden, provided you follow a few guidelines.

Should You Mulch Your Vegetable Garden?

Mulching your vegetables is a step you shouldn’t skip, after all the hard work you’ve put into preparing your soil and planting.

A mulched garden will retain moisture, cutting down on the time and energy (and in some cases, money) spent in watering your plants. Mulch suppresses weeds, feeds the soil as it breaks down, prevents soil erosion, and regulates soil temperature, protecting fragile root systems against extreme weather conditions.

Furthermore, it protects certain vegetables, such as squash and melons, from blemishes or soft spots that develop from sitting on exposed soil.

Can You Use Grass Clippings in Your Vegetable Garden?

Grass clippings are one of the most popular forms of mulch, largely due to being readily available – you’re growing your own mulch as you maintain your lawn! The fact that they’re free, and only require a small bit of preparation to ensure success, makes this mulch choice even more appealing.

Grass clippings release three important nutrients as they break down – nitrogen, phosphorus, and potassium, and unlike store-bought straw, you’ll know your mulch is free from harmful chemicals.

How to Use Grass Clippings in the Vegetable Garden?

Grass Clippings in the Vegetable Garden

The most important step in preparing your grass clippings for mulch is to make sure they are completely dry. Using freshly cut clippings in your garden can create several problems. The nitrogen the clippings release during decomposition causes them to heat up, which has the potential to “burn” your plant’s root system.

Also, fresh clippings that are full of moisture will mat together as they break down, creating a barrier that prevents rainwater from flowing through. Using fresh clippings could potentially result in a slimy, overheated mess which may even tempt slugs and insects to take up residence.

Drying your grass clippings is an essential step, and easy to do. Watch the weather forecast for a few sunny days over which to dry your clippings. Here is how you do it:

  • Gather your grass clippings after mowing and transport them to a tarp or designated area drying – if you perform this step directly on your lawn, be aware you may wind up with a temporary brown spot afterward. Use a patio/driveway to avoid a dead lawn.
  • Spread the clippings out with a rake to an approximate depth of 2”
  • Let dry for 1 – 2 days while flipping the grass to expose the green side
  • Your grass clippings will turn golden brown when completely dry

Read our related post on “How to Dry Grass Clippings?” here.

After drying, your grass clippings are ready to be used in the garden. Spread clippings in a thin layer, no more than 2 – 3 inches deep, leaving space around the stems of your plants. Watering the garden beforehand will help to keep the grass in place.

Dry Grass Clippings in Vegetable Garden: spread 2-3 inches deep

Avoid compressing the layer; you want oxygen to be able to flow through. Any dried clippings left over can be stored in a leak-proof container for future use, or just add them to your compost pile to let the grass decompose.

When spread in a thin layer, the clippings will begin to break down within weeks, supplying your plants with free fertilizer!

When added to a compost pile, clippings will take a few months to break down.

Over time, you’ll see the level of mulch diminish as the clippings deteriorate, becoming part of the soil. Simply add more dried clippings to keep the thickness at an optimum level.

Does the Type of Grass Matter?

Fear not, all types of popular grass varieties can be used for vegetable garden mulch, provided the clippings are properly prepared, and exclude the circumstances listed below.

When NOT to Use Grass Clippings in Your Vegetable Garden?

It’s important to know exactly what the grass was exposed to while growing, so using clippings from your own lawn is the best choice. For this reason, you should never use grass clippings from an unknown source.

Stay clear of grass clippings from a lawn that has been:

1. Treated with any pesticides

Pesticides you use on your lawn were not tested to be food safe, and the chemicals may leach into your vegetables.

2. Treated with a chemical fertilizer

Although it might seem like a good idea – fertilizer is fertilizer, right? – lawn fertilizer is structured differently and contains too much nitrogen for your vegetables and fruits. Too much nitrogen can kill your plants.

3. Filled with weeds that have gone to seed.

Although a few weeds in your grass clippings won’t hurt anything, if you examine the weeds in your lawn and find they contain seed heads, don’t use the clippings in your garden. You’ll end up sprouting those same weeds amongst your vegetables.

Clovers, on the other hand, can be useful to include in grass clipping mulch. Perennial clover varieties, such as Dutch white clover, are beneficial in the mixture as they change the structure of the clippings, aerating it and helping to prevent compacting.

4. Showing signs of disease or fungus.

Brown patches or specks of rust on your grass are some of the signs that your lawn is not healthy. Play it safe and don’t use grass clippings from these lawns for your vegetable garden to avoid possible cross-contamination.

5. Infested by insects.

If your lawn is overrun by harmful insects, think twice about using the clippings in your vegetable garden, as their eggs may survive the natural “heating” process of the nitrogen release, and hatch in your garden.

Beyond drying the clippings and spreading them as mulch, grass clippings can also be harvested for making an organic, liquid fertilizer for your vegetable garden. Follow these steps.

  1. Fill a bucket 3/4 full of fresh grass clippings (no drying needed).
  2. Top off the bucket with water.
  3. Let sit for 3 – 4 days, stirring once per day.
  4. Strain the solids out (you can add them to your compost pile). The liquid you are left with is homemade organic fertilizer, rich in nitrogen.
  5. Use sparingly, applying only about 3/4 cup at the base of each plant, or dilute with water. For best results, avoid splashing on foliage, as nitrogen may contribute to leaf burn.

What are Some Alternative Mulch Options for Vegetable Gardens?

Although grass clippings can be a free, easily accessible mulch for your vegetable garden, some gardeners may choose not to use them, especially around produce such as leafy greens, to which grass blades can stubbornly stick, calling for more vigorous washing. Some alternative mulches for your vegetable garden.

  • Aged compost
  • Bark and wood chips
  • Dry leaves, either whole or chopped with a mower’s mulching attachment
  • Shredded newspaper (no color ink)
  • Pine needles
  • Straw or hay (may have weed seeds)

As you can see, there are many options for mulching your vegetable garden that won’t break your piggy bank. Take advantage of what nature has provided, and you’ll find your garden, and your wallet, are both happier for it.

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