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Compost vs. Mulch: What’s Best for My Yard?

A homeowner holding a handful of compost

Many homeowners don’t understand the differences between compost and mulch, which makes it hard to know which would be more beneficial for their yards. It can be tricky to determine which one you should use, not to mention where and when, especially since both compost and mulch play important roles in helping grass and plants become part of a flourishing landscape. People also sometimes use the terms compost and mulch interchangeably, although these are actually two very different things with distinct benefits and potential applications in your yard. By taking a deeper look to learn more about what each one is and what it’s best used for, you’ll better understand what to use for your particular situation.

Let’s start with compost. This is the stuff that starts out looking something like food waste and winds up looking a lot like dirt, once nature has taken its course and the compost has developed into a form that is beneficial for gardens. Why does compost look like garbage in the beginning? Because that’s essentially what it is—cast-off bits of fruits, vegetables and other kitchen scraps that would otherwise go into your garbage can, if you didn’t toss them into the compost pile instead. If you don’t want to go to the trouble of maintaining a compost bin, you can purchase this soil amendment at your local hardware store.

While compost looks a lot like regular soil, as you can see in the picture above, it should never be used as straight potting soil—it’s too rich with nutrients. Rather, it should be added to soil to enrich it, especially if the soil has been depleted over time. Soil quality naturally degrades because of foot traffic, weather conditions like heat and drought and the ongoing nutrient demands of the plantlife that it supports. When you spread compost over your lawn or mix it into the earth in your garden before planting new bushes, flowers or vegetables, plants gain needed nutrients, which facilitates growth.

While mulch can be used as compost (and compost can be used as mulch—and often is by many gardeners), mulch and compost are not the same thing, and mulch has its own distinct role in a yard or garden. Compost is decomposed organic matter that looks a lot like soil, but mulch tends to be much coarser and has a variety of appearances, depending on what it’s made of—and it’s not always made of organic materials, though it usually is.

The term mulch refers simply to any material that is spread over the top of soil in order to regulate the soil’s temperature during extreme heat or cold, while keeping weeds out and moisture in. Mulch is also used for other purposes, including helping to prevent soil erosion and giving your yard or garden a neat, maintained appearance. And depending on what the mulch is composed of, it can add nutrients to the soil it protects, thereby supporting plant growth.

A common type of mulch used by many home gardeners is chipped bark from cedar or oak trees. Other types of mulch are made out of broken-down nut shells, small stones or even chunks of plastic. While rocks and plastic won’t add nutrients to the soil, they can improve the appearance of a yard or garden bed and offer some of the other benefits of mulch, such as weed and temperature control. Shredded leaves, pine needles or grass clippings can also be used as mulch that will protect and improve the soil.

So, when should you use compost in your yard or garden, and when is mulch a better choice? Compost should be used as a top dressing for soil to help grass and plants thrive; it can also be mixed into the soil in planters or garden beds when planting new flowers, bushes, vegetables and the like. Mulch, on the other hand, should be used as a top layer to beautify your outdoor landscape while protecting the soil from heat, cold and moisture loss. A layer of mulch will also prevent the growth of weeds, which can rob your other plants of needed moisture and nutrients.

Mulch made from organic matter will need to be refreshed or replaced at least annually, if not more often, and can be added throughout the year. Compost can also be used throughout the year, but plants can better take advantage of its benefits at the start of the growing season and then periodically thereafter during peak growing times until they enter their dormant period in the fall. Hiring a lawn care specialist is a great way for busy homeowners to keep up with their yards’ mulching and composting needs, since landscaping professionals can set up regular yard maintenance schedules and determine which type of product is best for any purpose or area of your yard.

If you decide to take on this project yourself, there are a few other things you should know, including how to properly mix compost into your soil and what’s going wrong if weeds are sprouting in your mulch.

A full compost pile that is ready for mixing the compost into soil

Mixing Compost Into Soil: Tips and Information

Mixing compost into soil in order to help your plants flourish is a relatively simple process, but there are a few things to know before you start planting with compost. First, as we mentioned, you can purchase compost from your local garden center, but you can also make it yourself by letting organic matter decompose into a soil-like substance that is rich with nutrients to help new plant life grow. The catch is that making your own is that it isn’t fast; it will take anywhere from several months to a year or more to create nutrient-rich compost that is ready for use in your yard or garden.

Starting your own compost pile begins with saving kitchen scraps, including unused bits of fruits and vegetables, or produce that is past its prime, along with coffee grounds, eggshells and other items, and mixing these materials with soil, plant clippings and other organic items to start the decomposition process. Some gardeners make compost in a pile that they either allow to sit or turn occasionally with a shovel in order to speed up the decomposition process. Others use outdoor tumblers or other specialized bins that make it easy to turn the compost and help it develop over time. Some materials break down faster than others, so you may decide that composting oak leaves or some other types of lawn waste is too much trouble. In these situations, you may decide to keep a separate pile for leaves or opt to use a layer of leaves in some parts of your yards much in the same way you might use mulch.

Mixing compost into soil can maximize your soil’s potential when it is added to garden beds, planters or the entire yard. You can add compost to potting mix in a planter, for example, or use it as mulch over the top of your garden beds or spread it over grass as a top dressing to enrich the soil beneath. Different soils in different regions contain varying levels of nutrients, of course, so some home gardeners purchase soil test kits to determine which nutrients are lacking, in order to decide what type of compost will be of most benefit to their specific yards.

Using compost effectively can turn into quite an undertaking, and if your soil is especially depleted from extreme weather, foot traffic or overuse, a lawn care specialist can be instrumental in determining the right type of compost for your needs as well as doing the physical labor involved in applying it in the best areas to have the most impact. Landscaping professionals can also handle regular lawn care, including re-applying compost as needed throughout the growing season.

Although mulch is supposed to help prevent the growth of weeds, it’s easy to make a small mistake that can lead to weeds growing in your mulch.

A purple hyacinth next to weeds that are growing through mulch

How to Stop Weeds From Growing in Mulch

There are many benefits of mulching, such as helping soil retain moisture during periods of low rainfall, regulating soil temperature during both the hottest and coldest months of the year and discouraging weed growth in a garden. Still, many homeowners do find weeds growing in their mulched garden beds from time to time and wonder how to stop weeds from growing in mulch. Here are some tips for keeping your mulched beds weed-free.

If you see just the occasional weed here and there, it probably isn’t cause for worry. Weeds can be removed relatively easily, simply by pulling them out. Keep in mind that you’ll want to remove the whole plant, including its roots, if possible, to prevent future weed growth in that area. If there are more than just a few weeds growing in your mulch, it’s time to assess what the problem might be and how to remedy it.

Remember, weeds aren’t just unappealing to look at. These unwanted plants can actually harm the surrounding landscape by taking up water and nutrients that would otherwise benefit the wanted plants in your yard or garden. This is why it’s important to keep your yard and garden beds as free of weeds as possible. If you have mulched areas of your yard that are prone to weeds, the first thing to determine is whether the mulch was applied properly in the first place.

A layer of mulch that is too thin, for example, will allow weeds to grow in the soil below, while a layer that is too thick can actually support the rooting and growth of weeds in the mulch itself. Installing a layer of weed barrier before laying the mulch over the top can also help reduce weed growth over time. There are many different types of weed barriers; many home gardeners use anything from newspapers or black plastic garbage bags to rolls of landscaping fabric designed specifically to allow air and moisture to penetrate the soil while discouraging weeds from taking root.

When you’re applying mulch to your garden, plan for a layer that is between two and four inches deep (any deeper than that might prevent water and nutrients from reaching the roots of your wanted plants and trees). It’s a great idea to lay mulch around trees to support their growth, but be sure not to pile mulch up around the trunk, against the bark. Mulch should be kept at least six inches away from the tree to avoid rot. As we’ve already mentioned, mulch will need to be replenished over time to keep weeds from filling in any gaps in coverage, as this layer will degrade after heavy rainfall and because of foot traffic and other natural and human-related alterations to your landscape.

ABC Can Keep Your Yard Healthy and Lush

There are many benefits to applying compost and mulch to your yard. However, figuring out how much to apply and when to apply it, and not to mention the physical labor, isn’t the way many of us want to spend our free time. Instead of spending your weekend trying to figure out your lawn care schedule, let ABC Home & Commercial Services take this task off your plate. In addition to lawn care services, we can help with a variety of landscaping projects, so you benefit from enhanced curb appeal and more free time on your hands.

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