With so many types of mulch available, it can be difficult to choose which one to use. Here's what you need to know to pick the best mulch for your landscape.
While mulching may seem like a basic part of gardening, there are plenty of different types of garden mulch and benefits that each type provides. Though shredded bark might immediately come to mind, there are other types of mulch that you can use in your garden (and pros for each one!). Knowing when to add mulch to your garden, and how much to use, is also important for keeping your plants happy and healthy. Keep these tips in mind as you’re planting your spring garden, and throughout the entire year if you decide to add any new beds or landscaping.
Benefits of Mulch
There are a number of advantages to adding mulch in your garden. In the summer, mulch helps the soil hold moisture so you don't have to water as often. In the hot sun, soil also tends to dry out faster and harden. Mulch will help protect the soil from direct sunlight and keep your plants happy.
Mulch also prevents weeds. Adding it to your planting bed will block light from openings in the soil and keep weeds from sprouting. By adding a thick layer of mulch, you'll ensure that the weeds never see the light of day!
Test Garden Tip: While a concentrated layer of mulch is ideal, don't overdo it. The best depth for a mulch layer is 2–4 inches. Any deeper, and it can be difficult for oxygen to reach the soil, which can cause your plants to suffer.
Over time, garden mulch types made from organic materials break down and increase your soil's structure and fertility. This is especially true with compost used as a mulch, as the nutrients will promote soil organisms and aid in plant growth.
When to Mulch
Every spring, check on the mulched areas of your garden and add more if the layer is starting to get thin. If you're mulching a large area of your yard for the first time and not just touching up a few garden beds, you might want to look into getting a delivery from a bulk supplier. It'll be less expensive than buying a ton of bags of mulch from your local garden center, and you won't have to haul all of the bags to your yard either.
When late fall rolls around, check on your mulch again, and reapply if needed. In the winter, a good layer of mulch helps regulate the soil temperature. Make sure it's already cold out if you're adding mulch in the fall; once the ground has frozen a few times, you can add more mulch as a protective layer.
Types of Garden Mulch
Not all mulch is exactly the same. Though shredded bark might come to mind first when you picture mulch, you can use other materials too, including straw and pebbles. Depending on your landscape and what your planting, each of these five choices can make wonderful mulch.
Shredded bark is one of the most common and least expensive types of mulch. It comes from a variety of sources, including cedar trees. Shredded bark is one of the best mulch types to use on slopes and it breaks down relatively slowly. Some shredded-bark products are byproducts from other industries and are considered environmentally friendly. Check the mulch packaging for more information.
Test Garden Tip: Shredded bark can take up some nitrogen from the soil as it decomposes. If you have poor soil, adding some organic fertilizer to the soil can help keep your plants healthy.
Straw mulch has a beautiful golden color that looks great in the garden. It's also a bit slower to break down than leaves or grass clippings. Some gardeners like smaller, more shredded straw pieces while others prefer larger straws. Straw is classically used in more utilitarian gardens, such as vegetable gardens, and under strawberry plants. Straw does a great job of keeping mud out of your edibles.
Test Garden Tip: Make sure the straw is free of weed seeds, otherwise it can cause more weeds than it prevents. (Oat straw is often particularly weedy.)
Compost looks like soil, except it's darker, so it really sets off plants well. This mulch material breaks down quickly but adds to your soil structure the fastest. Plus, it's inexpensive; you can create your own rich compost for free, even from grass clippings and leaves. Many municipalities give away compost as well.
Pine or Cedar Bark Chips
These bark nuggets are slower to break down than shredded bark, but they don't stay in place as well. They're not the best type of mulch for slopes or other areas where they may be washed away by heavy rain; the chips tend to float and take off like boats. The nuggets are available in a variety of sizes; the bigger the nugget, the longer it lasts.
Stones and River Rock
Because they're inorganic materials, stone and river rock don't break down in the landscape, so they don't need to be reapplied every year. However, it also means they don't improve your soil over time. Take caution when using stone as a mulch, because stones tend to get really hot. Stones are often used in cactus and rock gardens. If you decide to use rocks and stones as a mulch, cover your soil first with sheer landscaping fabric. This will prevent weeds from growing.