Grass Clippings as Mulch in Flower Beds | Top Tips for Success

Grass clippings are fantastic mulch to add to flower beds. You can add green grass clippings in thin layers on top of the soil around your flowers or let the grass dry out and use it as mulch. Dry grass clippings will break down even quicker to improve your soil if mixed with dry fall leaves or bark mulch. Avoid using grass clipping with weed seeds as these can sprout in your flower beds.

This article will explore all you need to know about using grass clipping as mulch in flower beds. This includes whether or not you should mix them through your soil and the best ingredients to mix with grass clipping for the best mulch.

How thick grass clippings should be for mulch

If you are using pure grass clippings, it is best only to layer ½-1 inch of grass much at a time. You can layer it thicker if you mix it through with other mulch types like dry leaves or straw.

Grass clippings can cause too much water to be held against the soil and cause rot. The other problem that can happen with thick layers of grass mulch is that it can stop water from reaching the soil. Green grass clippings are more likely to get soggy and rot while dry grass can stop the water from getting through.

Because if this it is best to layer around ½ an inch of grass mulch and layer on top of with bark chips or straw. This will mean that water can still reach the soil and the different ingredients can mix together and feed the soil.

Usually you would lay mulch 2-3 inches thick on flower beds to keep weeds away and keep the moisture in the soil. This will be too much if you are using grass clippings unless you mix them with other ingredients. You can then layer 2-3 inch layer of a mix of grass clippings, dry fall leaves, pea straw or hay.

How to use green or brown grass clippings as mulch

Green grass clippings

You can use either green or brown grass clippings as mulch. I like to layer a thin sprinkling of green grass clippings on the surface of my existing mulch. It will slowly break down, add nitrogen to the soil and will dry quickly.

Brown grass clippings

To use brown grass clippings successfully as mulch layer 1/2 -1 inch over the surface of the soil. Make sure the clippings don’t have any weed seeds and layer it thinly. You can also mix through dry grass clippings with other mulch ingredients.

Try mixing dry grass clippings with bark mulch, sugar cane, straw, hay, fall leaves or pea straw. These dry, brown ingredients are a great mix with grass clippings. They are the brown material that will work well with around 30% grass clippings.

This could also be added to a compost pile to break down. You can then place the compost on top of the soil as a top dressing after around 6 months.

Mixed brown grass clippings around my lily pilly.

My mix of grass clippings and leaves started to turn to mulch after around 6 months in a compost bag.

This mix of grass clippings and fall leaves has started to break down after around 6 months. While not fully broken down it is perfect for mulch.

Mixing grass clipping into the soil for flower beds

It is best not to mix grass clippings into soil. As the grass clippings break down in the soil there will be a temporary update of nitrogen from the soil as the bacteria break it down. This can cause your plants to turn yellow. The grass clippings will also stop the soil for holding water as well as it will create lots of air pockets.

Grass clippings should only be used as mulch or mixed through your compost bin to turn into compost.

Best ingredients to mix with grass clipping for mulch

Mixing other ingredients with your mulch is a great way to turn it into a superpowered mix with lots of carbon and nitrogen which will balance out and turn into compost. It will feed soil bacteria and worms while protecting plant roots and preventing weeds.

Here is a list of my favorite ingredients to mix with grass clippings to make a great mulch for flower beds.

  • Straw mulch
  • Hay
  • Pea straw
  • Sugar cane mulch
  • Lucerne mulch
  • Dry fall leaves
  • Compost
  • Mushroom compost
  • Bark mulch

When to use grass clippings as mulch

If you have a small amount of lawn, you can rake up grass clippings and sprinkle them straight onto flower beds. It will break down and feed the worms while protecting your plants from excess water evaporation from the soil.

I like to add it each time we mow our small lawn as it will only add a thin layer to the mulch. This means it will break down easily and will not starve the soil of oxygen.

Use a rake to pick up grass clipping either green or brown.

Another option is to let the grass clippings dry on the surface of your lawn over a few days. It can then be raked up when it is dry and added to your flower beds in a 1 inch layer or mixed with other mulch ingredients.

Leaving grass clippings to dry for 2-3 days on your lawn will not damage the lawn as long as there are long large clumps or layers. I like to regularly keep our lawn trimmed which means there is only a small amount of grass clippings at a time.

For mulch that breaks down rapidly, you can set your mower to the mulch mode which will chop the grass into finer pieces and it will break down quicker.

Grass Clippings as Mulch in Flower Beds | Summary

You can use grass clippings as mulch in flower beds if you layer it up to 1 inch thick or mix it with other mulch ingredients. Grass clippings can also be broken down in a compost bin over around 6 months. Mix a small amount with some fall leaves and you will have compost in around 6 months.

Grass clippings are a high nitrogen organic material that will break down quickly and feed the soil.