Tips for Applying Mulch Around Trees

Tips for Applying Mulch Around Trees

In a couple of our recent blog posts we wrote about the importance of applying mulch around trees.  Mulch has a number of benefits such as retaining soil moisture, potentially adding plant matter to the soil, regulating soil temperature, and lessening weed growth.  With these benefits in mind, we thought we would share some tips for applying mulch around trees.

What Type of Mulch to Use?

There are a number of choices for mulch including ground wood, bark, pine needles, straw, stone, rubber, and other options.  Consider using a mulch that will biodegrade and that doesn’t have added dyes or chemicals.

How Deep Should the Mulch Be?

As a rule of thumb, aim for between two and four inches of depth for mulch.  If you apply too little, it might not be as beneficial.  If you apply too much, it could lessen the amount of oxygen the roots of the tree get.

When applying mulch, try to have a consistent depth around a tree, rather than having it mound near the base and thinning out as you go farther away.

How Far Out From the Tree Should the Mulch Go?

As a general idea, aim for a mulch diameter of around six feet for every two inches in diameter of the tree trunk.  This might not be something you could do for larger trees, but generally speaking, going out farther is better than not going out far enough.

When applying mulch around a tree, be careful that it doesn’t touch the base of the tree.  There should be a space of at least three inches between the base of the tree and the mulch around it.  Having this space can prevent moisture from being retained near the trunk of the tree as well as other problems.

How Much Mulch Should You Buy?

Mulch is often sold in bags that are measured in cubic feet.  The bags might note how many square feet the bag will cover up to a certain depth.  For example, the bag might say it covers ten square feet at a depth of three inches.  To figure out how much mulch you need, if you apply it to the depth noted on the bag, you can simply calculate the total square footage you need and buy the correct number of bags for that.  If you are applying the mulch at a different depth or the depth isn’t noted, you could calculate the cubic feet by calculating the square footage and multiplying it by the depth measured in feet.  To do this, you would convert the depth in inches to feet.  So, for example, if you wanted to apply 3 inches over a space that was 100 square feet, the 3 inches would become 0.25 feet (3 inches/12 inches) and that would give you 0.25 feet * 100 square feet = 25 cubic feet.

When applying mulch, a border can be helpful in keeping it around trees.  Borders could be made from plastic, stone, or other materials.

Reapply

Mulch doesn’t last indefinitely.  Mulch can be washed away by rain or blown away by wind.  If the mulch you have biodegrades, that will happen over time.

One tip is to periodically check the mulch around your trees.  You could do this each once per season checking the depth and the condition of the mulch and reapplying or replacing as needed.