How Much Mulch for Healthy Plants?

low level shot of garden mulch 300x170New gardeners sometimes buy mulch without calculating how much they need to use, but that’s a mistake. Buying too much is wasteful, but buying too little is even worse because a healthy supply of mulch is vital for plant growth. Deciding how much mulch to use can be challenging, since it will depend on the type of mulch and the style of gardening that you use, but it’s worth taking the time to get it right.

General Rules

While there are some exceptions, most gardening methods follow the same rules for mulch. The size of the particles in the mulch will determine how much you should apply around the plants. The size matters because it effects how much air and light can get through the mulch to the plants that are living under it. Small particles tend to clump together, so they let relatively little air and light through. Large particles can’t fit together without leaving gaps, so they offer more ventilation.

In most cases, you should only apply a two to three-inch-thick layer of mulch around your plants if the mulch’s particles are small. This is the case when using mulches made from compost, finely-shredded bark, or anything else that can fit together in a tight clump.

If your mulch is made up of straw, stone, pine needles, or larger pieces of bark, you should use a thicker layer. Three to four inches is appropriate for most uses, but there will be some variance based on the environment and the plants that you are growing.

No-Till Method

There are a few methods that need much more mulch, and no-till farming is the most popular of them. It isn’t a great choice for growing a lawn, but it’s ideal for flower beds and vegetable gardens because it saves labor and often leads to larger, healthier plants. The method uses mulch to suppress the growth of weeds and to trap water in the soil, so using the proper amount is vital.

Most gardeners prefer to use a layer of mulch with large particles, with straw mulches being the particular favorite. A no-till garden can benefit from a layer that is between eight and ten inches thick, so you should be ready to buy mulch in bulk. That may seem like a lot, but the heap will shrink on its own over time as it breaks down and gets integrated into the soil. Be sure to apply the mulch without packing it down to make sure that the method works properly.

Stay Flexible

It’s important to remember that there are a lot of variables that can have an impact on the garden, such as the local weather, the plants that are growing, and how much water it gets. All of those factors can change how much mulch that it needs, so you should always keep a close eye on your garden and be ready to make adjustments from season to season. If you do, you can be sure of applying the perfect amount of mulch to get healthy and beautiful plants.

The folks at Melvin Mulch know mulch. Got mulch questions? Call the Mulch Answer Line at 414-856-9077.

Photo by Ted Eytan from Flickr using Creative Commons license.