Mulch: A How-To for the Landscape

Mulch can make your landscape more attractive, but it is also an important part of keeping your trees, shrubs, and garden healthy. Some benefits of mulch include moisture preservation, weed control, soil temperature regulation, erosion prevention, and protection from lawn equipment.

Mulches come in two forms:

Organic 

These mulches are made of organic materials that decompose over time, including leaves, compost, pine needles, and pine or hardwood bark. Keep in mind that these mulches need to be replenished periodically and may need other maintenance.

Inorganic

These mulches are inert materials that do not decompose, including gravel, plastics, and recycled rubber tires. These mulches work best when you apply landscape fabric to the area first. This keeps the material from sinking into the soil.

When do you mulch?

Mid-spring, after the soil has warmed, is the ideal time to mulch flower beds and vegetable gardens. If you apply mulch in the winter, wait until the soil cools but don’t let it freeze. Mulch can help any new planting retain moisture until the roots are established. Our MSU Extension publication, Mississippi Vegetable Gardener’s Guide has more information about mulching a vegetable garden.

How do you mulch?

Mulch should be applied at the proper depth for plants to benefit. Depth varies with each mulch type. Some mulches should be applied thicker than others. Check out the chart in our MSU Extension publication, “Mulches for the Landscape” for application rates, as well as the advantages and disadvantages, for many different types of mulches.

When mulching trees in the landscape, spread the mulch in a 3- to 6-foot ring around the tree and 4 – 6 inches deep. Do not pile the mulch against the trunk. Pull the mulch 2 – 3 inches away from the trunk. This helps prevent problems caused by moisture and rodents. 

How much do you need?

Whether you by mulch in bulk or in bags, you don’t want to pay for more mulch than you need. Bulk quantities are sold in cubic yards. Bagged mulch is sold in cubic feet. Here’s how to calculate what you need:

First, determine the square foot measurement of the areas to be mulched. For example, if you have a perennial/shrub border 5 feet wide and 20 feet long, the area to be mulched equals 100 square feet.

Now, if you are going to apply mulch 4 inches deep to this area, convert the 4 inches to a fraction of a foot: 4 inches / 12 inches = 1/3 foot or 0.33 feet.

Multiply this fraction by the square foot measurement of the area to be covered: 0.33 feet x 100 square feet = 33 cubic feet.

One cubic yard equals 27 cubic feet. In the example above, you need 1 cubic yard of mulch plus an extra 5 cubic feet of mulch: 27 cubic feet (1 cubic yard) + 5 cubic feet = 33 cubic feet.

Before you purchase mulch in bulk (by the cubic yard), compare the cost with purchasing your mulch in smaller units.

Bagged mulch is also available in amounts such as 1.25 cubic feet or 2.0 cubic feet. If you purchase the mulch needed for the example given above in 1.25 cubic feet bags, you will need 27 bags (33 cubic feet divided by 1.25 cubic feet = 26.4 bags). If you purchase bags of 2.0 cubic feet, you will need 17 bags (25 cubic feet divided by 2 cubic feet = 16.5 bags).

For more benefits, tips, and a chart to help you decide which mulch material to use and how much, download our MSU Extension publication, “Mulches for the Landscape.”