How to Choose the Best Type of Mulch for Your Landscape
With so many kinds available, it can be confusing when you're trying to figure out which mulching material to use. Here's what you need to know to pick the right mulch for your garden.
While mulching may seem like a basic part of gardening, there are a few must-knows about the different mulches you can use and the benefits that each provides. Though shredded bark might immediately come to mind, there are several other types of mulch that you may want to consider using in your garden. Knowing when to add mulch to your planting beds, and how much to use, is also important for keeping all your plants healthy. Keep these tips in mind as you’re planting your spring garden and throughout the entire year, especially 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 baking in direct sunlight and keep your plants happy.
Mulch also prevents weeds. Adding it to your planting bed will block light from reaching the soil, which keeps many kinds of weed seeds 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 an even 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 (those produced by or part of a living thing) break down and increase your soil's structure and fertility. This is especially true with compost used as a mulch because the nutrients in it will promote soil organisms and fuel plant growth. Plus, a layer of mulch can help fight climate change because covered soil holds onto carbon instead of releasing this greenhouse gas into the air.
When to Add 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 schedule a delivery from a bulk supplier. It'll be less expensive than buying a ton of bagged mulch from your local garden center, and you won't have to haul all of those bags in your vehicle 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 acts like insulation, helping to regulate the soil temperature. This reduces stress on plant roots and can prevent frost heaving where smaller plants are pushed out of the ground as it freezes and thaws repeatedly. Make sure the ground has frozen a few times before adding mulch as a protective layer for the winter.
Types of Garden Mulch
Depending on your landscape design and what you're planting, each of these choices can make a good mulch.
Shredded bark ($3, The Home Depot) 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 mulches 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 ($15, Tractor Supply Co) 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 around strawberry plants. Straw does a great job of keeping mud off 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 ($4, The Home Depot) 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
Often labeled as bark nuggets ($8, Ace Hardware), these chipped pieces of bark 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
Rocks tend to be more expensive than organic mulches. But because they're inorganic materials, river rock, stones, and landscaping pebbles ($45, The Home Depot) don't break down, 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 in the sun. Stones are often used in cactus and rock gardens. If you decide to use rocks and stones as a mulch in an area where plants won't be growing, such as under a deck, cover the soil first with sheer landscaping fabric. This will help prevent weeds from growing up through the rock.