How to Mulch
Erosion buster, moisture conserver, plant enhancer: Mulch is all those things and more. And learning how to apply mulch and how much mulch to buy can make gardening much easier and labor-efficient. Here are nine steps to learning how to mulch like a pro.
Mulch does a host of things that your plants want and need, such as shading roots on hot days, preventing moisture from evaporating, and stopping weeds from taking root. But it's important to learn the differences between mulch materials, and how to properly spread mulch.
Two Types of Mulch
There are two basic kinds of mulch: Organic and inorganic. Organic materials—wood, bark, compost, grass clippings, and leaves—will decompose and improve the soil. They last a few years, after which you'll need to add more. In addition, organic mulches are easy to spread and do no harm if mixed into soil, as will happen when planting annuals or shrubs, for example.
Stone, by contrast, is meant to be a more or less permanent mulch, to be put in place atop a layer of landscape fabric, and then left alone. It's the lowest-maintenance option but not easy to plant in. So the key question to ask yourself is: Will I be doing any gardening that requires digging and moving mulch aside to plant ornamentals? If the answer is yes, you will want to stick with an organic mulch.
Related: Grass Growing Up Through Mulch
Pick the Right Mulch
Every kind of organic mulch has pros and cons. For example, bark nuggets are widely available but can float away in heavy rain. Cocoa hulls have a distinct aroma (some like it, some don't) but are relatively expensive, and toxic to dogs. Shredded bark or wood is the most common landscape mulch—it's inexpensive and easy to apply but doesn't add as many nutrients to soil as some other mulches.
You can also use waste from your yard as mulch, such as grass clippings, leaves, and compost. Compost adds a lot of nutrients but isn't good at deterring weeds. If you composted it yourself at home, it's not a good idea to mulch beds with it, unless you know that the compost got hot enough to kill weed seeds. Otherwise, you might end up with more weeds, not less!
Grass clippings are effective as mulch but don't pile them too deeply or they can get soggy and mucky. And be sure never to use clippings as mulch if the grass was treated with herbicides. Leaves are an excellent mulch if they're shredded first. Pine needles are long lasting and an excellent mulch around acid-loving plants like azaleas, because pine needles acidify soil.
Tips for Mulching
Although the process of mulching seems simple (you just put it over the dirt, right?), there are some things to keep in mind. These are some of our best mulching tips.
- Calculate how much mulch to buy. There's nothing more frustrating than choosing the mulch you want and not having enough.
- Not too thick, not too thin. Spread mulch about 2 to 3 inches thick. Anything thicker could harbor pests, but at the very least is wasteful and unnecessary.
- There's no perfect time to apply mulch to beds. Your plants will welcome mulch any time of the year. If you apply mulch in late fall or early winter and you live in a cold climate, wait until the ground freezes before mulching.
- Mulch trees and shrubs properly. Mulching around trees and shrubs is a great way to prevent injury from mowers and trimmers. As with beds, spread mulch 2-3 inches thick. Do not pile mulch against the trunk like a volcano—this can encourage pests and diseases.