Published: October 14, 2009 06:30 pm      

Volcanoes kill trees

Mulching is a great way to conserve water in the landscape and insulate roots from extreme temperatures, whether hot or cold, as well as reduce weed competition in the landscape bed.

Volcano mulching around trees and shrubs, however, will kill quicker than lack of water will.

Too much mulch around the trunk prevents oxygen from reaching the roots and traps moisture, causing wood decay. Insects, fungi and bacteria then feed on the decayed wood, leading to wood rot and eventual death of the tree.

Mulch volcanoes also promote root growth in the wrong direction. Moist mulch is attractive to roots when the soil is either too wet or too dry; roots then grow up instead of down. Once that mulch volcano dries out, the tree becomes drought stressed. Additionally, the volcano shape acts like an umbrella, shedding water to surrounding grass instead of soaking in to tree roots.

The best way to mulch is to follow Mother Nature’s example. Natural mulch of fallen leaves is flat and approximately two to three inches thick. It extends from the trunk out to the canopy, also called the drip line. The roots of many established plants will extend two to three times the canopy spread of the top so mulch as big an area as you can, taking care to pull mulch back a few inches from the trunk to allow for air space.

For more information on this or other gardening topics, please contact Brenda Jackson at (706) 278-8207 or e-mail bljackson@whitfieldcountyga.com. Also visit the Agriculture and Natural Resources page of www.ugaextension.org/whitfield.