Fall is a great time to mulch

SAN DIEGO COUNTY – “I know we’re supposed to do something to our trees in the fall, but what?” Tree owners often feel compelled to spray, prune or apply something to their trees and landscape plants on a regular basis. But, unless there is a specific reason to spray, prune or apply things to landscape trees, the best thing to “do” to keep your trees healthy is to apply a layer of mulch.

“Fall is a great time to be out in the yard spreading shovels-full of composted woodchip mulch under your trees,” says Tchukki Andersen, staff arborist with the Tree Care Industry Association. “Trees with mulched root zones are usually larger, more vigorous, develop faster and have higher rates of survival than plants surrounded by turf grass or bare dirt. Mulches retain soil moisture and reduce erosion and soil compaction.”

Mulched trees also have fewer weeds, which reduces the need for the roots to compete for limited resources. The soil under the mulch also likely stays warmer longer into the winter and also warms faster in the spring, helping extend the growing season for plants.

Organic mulches are a favorite among professional arborists, who view wood chips as an excellent and attractive mulch for trees. Other organic mulches include bark chips, ground bark, composted lawn clippings, leaves and straw. These mulches are high in cellulose and low in nitrogen, and should be free of weed seeds.

Good mulching

• How wide is wide? A good mulch bed should extend out at least three feet from a tree’s trunk in all directions, though extending out to the drip-line is preferred.

• How deep is deep? The mulch bed depth should be maintained at two to four inches.

• Go ahead; cover the grass! If there is grass in the area that needs to be mulched, put a five-page layer of newspaper over the grass, get it wet, then add mulch on top (this will help keep the grass from growing up through the mulch).

*Use the right mulch. For poor soils, use well-composted mulch to build up the nutrients. Soils that are healthy will do fine with a highly stable softwood bark (such as cypress bark), which doesn’t break down as easily.

A professional arborist can assess your landscape and work with you to determine the best treatment for your trees and shrubs if you like. Visit http://www.treecaretips.org for more information and referral to experts in your area.