Published: 10 March 2025

Mulch is one of the best ways to improve soil health in your garden. By regularly mulching, you can add nutrients, retain moisture, and suppress weeds. And best of all, if you make your own, it’s totally free. The trick is knowing how to do it properly.

Everything you Need to Know About Garden Mulch

What is mulch?

In essence, mulch is a protective layer of organic material, which can be spread on top of the soil. It’s made from general garden waste, such as leaves, grass clippings, or old, used compost. If you don’t have any of that, you can also use wood chips. Inorganic mulch, made from rubber is also available, but it’s not great for the environment and won’t enrich your soil, so it probably best avoided. But why would you use it anyway when garden mulch is so much more cost-effective?

Five steps for making and using your own garden mulch

Gather organic materials

A whole range of biodegradable materials can be used to create mulch. And in fact, the more diverse the materials you put into your mulch, the more effective it can be. So, look around your home and garden for some of the following:

  • Leaves—Great for a light mulch that breaks down quickly.
  • Grass clippings—High in nitrogen, best used in thin layers to prevent matting.
  • Wood chips or bark—Excellent for paths or around trees.
  • Straw or hay—Good for vegetable gardens.
  • Compost—Rich and nutritious, but apply under another mulch layer for best results.
  • Newspaper or cardboard—Works well as a weed barrier under other mulch layers.
  • Pine needles—Long-lasting and slightly acidic; ideal for acid-loving plants.

Prepare the materials

For best results, materials should be broken down before being used as mulching. Shredding items such as plant prunings, leaves, newspaper, and cardboard can help the materials decompose faster while preventing clumping. You can use a leaf shredder, lawnmower, or wood chipper for this process. Or simply place your materials in a large container and chop them up with some long-handled loppers or shears. 

Tip: If you are using a variety of materials, it’s also a good time to mix them together to create an even consistency.

Prepare your garden

If you’re short of time, you can simply spread your mulch over your garden bed as is. However, for best results, it’s a good idea to remove any existing weeds first. If it has been very dry, it can also help to water the soil before application.

Tip: If you haven’t fed your garden recently, it can be a good idea to add liquid fertiliser to your beds before spreading your compost. 

Apply the mulch

To be truly beneficial to your garden, mulch should be between 5cm and 10cm deep. If you don’t have enough to spread your mulch that thickly across your garden, it can be better to work in sections. Concentrate on the most needful part of the garden now, and do the other parts another time. If you spread your mulch too thinly, weeds will penetrate easily. Too thickly, and water may not be able to reach plant roots.

Tip: Alternatively, if you’re working with mixed materials, you can try layering your mulch. Placing cardboard on the bottom with straw, grass clippings, or wood chips on top. This technique is particularly useful if you’re looking to create a no-dig garden bed.

Tip: Mulching too closely to plant stalks and tree trunks can cause them to rot. Leave a gap of at least 5cm around each plant.  

Maintain your mulch

Mulching is never a one-and-done process. To maintain the health of your plants and soil, you should really apply mulch at least twice a year. 

Tip: Keep an eye on your mulch. If it doesn’t seem to be breaking down, it can be helpful to turn it or aerate it. This can speed up decomposition and prevent mould from forming.

Mulching is an integral part of maintaining a healthy garden, like Holker’s Gardens. In fact, our gardeners view it as one of their most important tasks. If done properly, it boosts soil nutrients while enhancing the aesthetic of your borders and beds. And it can be really satisfying to put all that garden waste to good use!Plan your visit to Holker Hall & Gardens here.