Use Mulch for Beauty and Weeds, Temperature Control | Lifestyles


The beginning of the gardening year is the best time to tackle some gardening tasks before we start planting our color and vegetables. Mulching your landscaped beds should be at the top of this spring checklist.

There are many options when it comes to mulching material, including pine bark, hardwood bark, and pine straw. The choice is really up to the gardener.

This publication from the Mississippi State University Extension Service is an excellent resource for choosing among different materials that can be used as mulch:

Newspapers, gardening magazines and landscape professionals tell us that the best thing we can do for our trees and shrubs is to apply a layer of mulch around the base. But opinions vary as to how much mulch to spread.

Many recommendations say 3-4 inches, and I’ve seen some suggest up to 10 inches, which is way too much. Never use so much mulch around your trees and shrubs that it looks like a volcano.

I think a 2-3 inch layer is sufficient for most applications.

Here’s why I say that. I have observed that the depth of the mulch layer in gardeners’ landscapes – mine included – tends to increase over the years. This is because of our desire for the mulch to look fresh.

I like to use the analogy that a new coat of mulch equals a new coat of paint which improves the appearance of a room. In an effort to keep the garden fresh, we end up reapplying and replenishing the mulch at a faster rate than it breaks down.

While this increased depth may not necessarily harm shrubs and trees, it may delay warming of the landscape bed in the spring, which will delay spring growth. It can also slow the cooling of the soil in the fall, which can eventually prevent plants from hardening off before winter colds arrive.

A good mulching rule to remember is to always go out in diameter around the tree or shrub with the mulch, not up. This means spreading the mulch horizontally and not stacking it vertically against the trunk.

I like to use my hands to pull the mulch off the tree trunk. As you pull the mulch back, contour it so it looks like a bowl. This helps it collect water and direct it to the root system of the tree during rain or irrigation.

Keeping the landscape mulch to a reasonable depth provides many benefits for our landscape planting.

In addition to mulch helping to moderate and maintain optimal soil temperatures – warmer in winter and cooler in summer – a good layer of mulch reduces weed seed germination by blocking sunlight.

Because we’re not constantly walking over mulched areas to mow or pull weeds, it reduces soil compaction and creates a great environment for the root zone. And adding mulch adds aesthetic beauty to your landscaped beds.

So remember these tips when applying mulch to your landscape this spring. Proper use of mulch will give you one more reason to look forward to a great gardening year in 2022.

Dr. Gary Bachman is Professor of Horticulture Extension and Research at Mississippi State University Coastal Research and Extension Center in Biloxi. He is also the host of popular Southern Gardening TV and radio shows. Contact him at [email protected]


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