Mulching may be your shrubbery’s best friend, especially during hot, dry periods of summer. In addition to retaining soil moisture, mulches suppress weeds and prevent crusting of the soil surface. Also, as mulch breaks down, it adds organic matter to the soils which acts as a natural fertilizer and great for soil structure.
“In most landscape situations, mulching material should be applied to provide a three-inch depth after settling. However, in a heavy clay soil, reduce mulch depth,” said Mallory Kelley, a. regional home grounds agent with Alabama Extension.
A variety of materials may be used for mulch added Kelley. Some popular mulches include:
- Pine Straw – Pine needles are long-lasting and do not mat down excessively.
- Grass Clippings – This material decomposes rapidly and has a tendency to pack down. Place only 1 to 2 inches of fresh clippings on the surface at one time. Do not use clippings from a lawn treated with weed killer.
- Pine Bark Chips – This material is attractive and is effective in weed control.
- Plastic Film – Back polyethylene plastic can serve as an effective mulch for long term weed control. It is unsightly but it can be covered with an attractive material such as pine straw. Don’t use plastic in poorly drained areas. It often causes the soil to hold too much moisture and reduces soil oxygen.
- Sawdust – Sawdust makes an effective mulch with a neat appearance. However, microbial breakdown of sawdust can rob the soil surface of nitrogen. This can be overcome by making several light applications of a nitrogen-containing fertilizer during the growing season.
- Straw – Straw from grains such as wheat, oats or rye is somewhat unsightly until it settles. It may also contain seed that will germinate, and it can be a fire hazard when very dry.
Other mulch materials include peanut hulls, pecan hulls, hay and newspaper.
Kelley does not recommend using landscape fabrics. “They are good for the first two or three years, but when the mulch you put on top of the fabric breaks down and turns into dirt that dirt allows a place for weeds to take root. With this happening year after year and as more dirt accumulates on top of the fabric, you then have a major mess on your hands and it is almost impossible to remove the fabric once stuff starts growing into the soil that is on top of the fabric.”
Have a gardening question? Call the Master Gardener Helpline. To reach the helpline, dial 1-877-252-GROW (4769).