Friday, August 3, 2012

Don’t Pile Mulch Against Tree Trunks

Applying organic mulch to the garden provides many benefits: improves the soil structure, adds micro and macro nutrients to the soil, conserves water during a drought, and acts as a food source for many beneficial microorganisms living in the soil.

When applying mulch around trees, however, an air space must be kept between the mulch and tree trunk so the bark can dry. A constantly wet trunk will provide a suitable environment for disease. This, of course, does not apply to all trees. For instance, the magnolias of the Southern States grow along streams and swamps.  But other trees, like citrus and avocado, are susceptible to crown rot.  

 If the fungal organism is present and the bark remains wet for a prolonged period of time, infection will occur.  Untreated, the tree will die. Don’t pile mulch against the tree, and don’t position sprinklers so the water hits the trunk. Keeping the tree trunks dry as much as possible is important.

In general mulch enhances the health of trees but precautions need to be observed.