These Are the Pros and Cons of Mulching Your Garden

There’s a lot to consider before adding mulch to a garden. Mulch is a layer of material that covers soil, and it can be both advantageous and potentially harmful for your plants. It can encourage water retention, but it could also attract unwanted pests. Before purchasing mulch in bulk, here are some pros and cons of mulching your garden, according to landscaping experts.

Types of Mulch

Mulch can broadly be categorized into two types: organic and inorganic. Organic mulch options include wood chips, bark, straw, compost, and even grass clippings. Inorganic mulches, on the other hand, include rocks, stone, gravel, rubber mulch, and landscape fabric.

“Each type offers unique benefits,” says Joe Gerrior, owner of Gerrior Masonry & Landscape Construction in Massachusetts. “Wood chips and bark for durability, straw and compost for enriching the soil, and rocks for decorative, low-maintenance areas,” he says.

Different mulches work best in certain climates. Organic mulches work well in temperate regions because they provide insulation and encourage moisture retention, says Samuel Davis, horticulturist and CEO of London Gardeners. In contrast, inorganic mulches like stone and gravel are better for hotter climates because they reflect heat and reduce evaporation. So, before deciding on a mulch based on looks, also consider the climate and its impact on your garden.

Pros of Mulching Your Garden

Mulch can be a low-maintenance garden or lawn solution, improving plant health and the overall aesthetic. Here are some of the main benefits of mulch:

Retains soil moisture

Mulch encourages soil moisture retention. Davis says allowing soil to be moist for longer periods of time leads to less frequent watering. This moisture retention helps plants survive extended periods of drought. Mulch can also be beneficial in instances where there are watering restrictions placed on neighborhoods.

Suppresses weeds

Not only does mulch keep water in, but it also keeps unwanted weeds out. So, to reduce how much attention and time you spent plucking weeds or spraying herbicides, lay down mulch instead.

Regulates soil temperature

It can be beneficial for a garden year-round, not just in the warmer months. “Mulch also regulates soil temperature, keeping it cooler in summer and warmer in winter,” says Gerrior. Mulch shades the soil, preventing it from getting too warm from the sun in the summer. Alternatively, it acts as an insulating blanket during cooler periods, giving the roots a stable soil environment.

Adds nutrients

There are many different types of mulch, including organic mulch which can eventually turn into a nutritional benefit for your garden. Over time, organic mulches decompose and enrich the underlying soil with nutrients. This decomposition adds organic matter to the soil, which benefits the long-term health of your plants.

Enhances aesthetic appeal

Mulch can impact not just how your plants grow but also how the garden looks. Gerrior notes that mulch enhances the aesthetic appeal of your garden. It offers a neat, tidy, well-maintained look that dirt just doesn't match. Also, mulch can come in different colors to suit whichever look you're going for.

Cons of Mulching Your Garden

There are also some potential problems that come along with adding mulch to your garden or lawn. Here are some cons to consider:

Suffocates the plant roots

Be careful not to apply too much mulch, as it can suffocate plant roots. Too thick of a layer can deprive roots of the necessary oxygen they need to thrive. To avoid cutting off the air supply, add at most 2-3 inches of mulch, and don't pack the mulch too tightly.

Attracts pests & disease

Mulch can create a supportive living environment for plants, but it can also support other unwanted garden companions. "It provides an excellent and moist habitat for pests and diseases,” Davis warns. As the perfect shelter, mulch can attract pests like roaches, ants, and termites, which could cause problems beyond the garden bed.

Thankfully, not all mulches attract these pests. Gerrior suggests cypress and cedar mulches that deter insects.

Impacts water absorption

While mulch can lock in moisture, too much mulch can impede water from getting to the roots. “Over time, mulch may form a crust, repelling water rather than allowing it to soak into the soil,” Gerrior adds. That’s why, even low-maintenance mulching may require occasional attention to ensure garden health.

Increases soil temperature

When it comes to regulating the temperature, certain types of mulch work better than others. "Inorganic mulches, though long-lasting, can increase soil temperatures and stress plants during hot weather," says Gerrior. Keep an eye out for hints that your plants are wilting or need more light and water than normal.  

Composting mulch is kept ideally between 110 and 160 degrees Fahrenheit. Be careful to water and cool your garden bed if you live in an area prone to high heat and desert temperatures. Mulch can spontaneously ignite.