The Truth About Gardening Mulch

There's nothing like the smell of fresh mulch to make an avid gardener's heart pitter patter with excitement. Why? It signals the beginning of the growing season. So whether you buy it in bags from the gardening center or get a whole truckload delivered to your house, the first whiff of that woody, organic aroma is unmistakable. And besides the initial sensory experience, mulch actually provides a plethora of benefits for your garden.

A healthy layer of mulch (we'll cover just how much to use later on) slows weed growth, which translates into fewer hours of backbreaking weed-pulling and maintenance for you. Additionally, the Water Conservation for Lawn and Landscapes says it protects your plants from water loss by shading the soil (which prevents evaporation) and guarding the delicate roots from hot, dry conditions or sudden drops to colder temperatures. Mulch also packs a punch in the aesthetics department, as a fresh layer tidies up the appearance of your garden, keeps plants looking their best, and maximizes your curb appeal.

What are the different types of mulch?

If you're a beginner gardener, it's normal to feel overwhelmed by all the different types of mulch available at your local garden center. But let's break it down: For starters, the variety of mulch you choose will either be organic or inorganic. Now, within these two categories are lots of subcategories and spinoffs.

Organic mulch is an excellent choice for your garden because it provides nutrients to the soil as it slowly decomposes. The most common types of organic mulch are wood chips and shredded bark. However, other organic options include grass clippings, straw, leaves, compost, and pine needles, according to Good Housekeeping. Wood chips are most commonly used for flower beds or other prominent planting displays, as they provide an attractive, crisp appearance. Straw and grass clippings are great choices for vegetable gardens.

Inorganic mulch doesn't decompose and therefore lasts a lot longer than organic mulch. If you want to save money in the long run or not worry about reapplying a layer each year, inorganic might be the best choice for you. Your options in this category include rocks (stones or lava rocks), landscape fabric, or chopped up rubber. Bob Vila says that rocks are a great option for lining paths or walkways, but they're not the best choice to use around plants because their heat absorption and retention can actually burn or damage your plants.

When and where to apply mulch

Though the exact timing depends on the climate where you live, it's a good rule of thumb to lay your mulch in mid-to-late spring, says Martha Stewart. You don't want to do it earlier than this, because a thick layer of mulch will prevent the soil from adequately thawing and warming up after a cold winter — and your soil needs to be warm in order to best support plant life. An exception to this timeline is if you have perennials that'll begin blooming in the spring. Your best bet is to mulch around them when they're dormant. Check the care instructions for any perennials you have to make sure you mulch at the appropriate time.

You can spread mulch throughout your flower beds, shade gardens, and veggie patches. When it comes to trees or shrubs, Good Housekeeping urges caution before you pile it on. Too much mulch around a tree's trunk or the base of a shrub can cause root rot and also provide a perfect spot for rodents to nest. If you're adamant about placing mulch around your trees/shrubs, Good Housekeeping suggests laying your mulch six to 12 inches away from the tree trunk or shrub base.

How much mulch should you use?

Even though mulch is a wonderful addition to your garden, too much of it can negate all of the benefits and wind up harming your plants. Not sure how much to spread in order to reap the benefits but not suffocate the flowers? Country Living suggests an even depth of two inches across the garden bed. Depending on the type of mulch you're using, you might be able to get away with a little more. Varieties like pine bark nuggets don't impede airflow as much as traditional mulch, so you can increase to depths around four inches.

Now that you know how deep to spread your mulch, you need to determine the total quantity to buy to cover all of your gardening needs. Because you buy mulch by the cubic yard, Country Living offers a formula to figure out how much you need to buy. (Who knew you'd use math equations in gardening?) First, calculate the square footage of your garden bed or area you're mulching. Then, multiply your square footage by the desired depth of mulch, and then divide by 324. This will give your cubic yard requirements, and then you can head straight to the nursery to buy as much mulch as you need.

Mulch can help you combat weeds

As previously mentioned, mulch is a highly-effective barrier in your battle against weeds. It blocks sunlight from reaching the weeds, so in turn the seedlings don't have enough energy to push through the barrier and reach the surface. However, mulch can't stop every single weed in its path, especially pesky dandelions (compliments of all those fluffy seed heads).

However, there are some things you can do to optimize weed resistance. For starters, before you spread any mulch, pull all the weeds in your garden bed. It's important to remove the entire root of the weed, or else it will pop right back up. The best time to remove weeds? Try to do it after a heavy rain so that the ground is saturated and your task will be much easier.

Fine Gardening says that crickets and carabid beetles can live in organic mulch and these critters will search for — and eat — various weed seeds. This means less work for you and full bellies for them!

Does the color of mulch matter?

The color of mulch you choose tends to come from personal preference and how the color will enhance what you're planting. But aesthetics aside, does the color of mulch matter? Is there any correlation between a certain shade and its performance?

Some people fear that dyed mulch will be bad for their soil. Gardening Know How says this can be true to an extent, and advises gardeners to avoid buying ultra-cheap mulch. The reasoning is that cheap dyes (found in some inexpensive mulch) can contain harmful chemicals which will then seep into the soil and negatively impact your plants.

Colored mulch can also be a popular choice because plain (non-dyed) organic mulch usually fades to a grayish hue after about a year, says Family Handyman – and your plants may not look as vibrant against the subdued gray mulch. However, dyed mulch may keep earthworms away from your garden; they don't like the chemicals it releases into the soil. Since earthworms are a critical part in every healthy garden ecosystem, you may want to choose an organic, non-dyed mulch to ensure the earthworms stick around.