Mulching Trees

The number of weekend gardeners in my neighborhood is evidenced mainly in spring. I can ascertain the novice gardeners from experienced experts by the quantity of mulch in the corner of their driveways. Joe, who has fifty bags of mulch delivered to mulch four trees, mulches improperly. But Gladys, who has a small pile of mulch delivered to mulch six trees, is an expert. A weekend later, Joe's trees look as if they are sprouting from mulch volcanoes at least a foot deep, while Gladys' trees are mulched in a large circle, about three inches deep, and several inches away from the tree trunk.

Many people make the mistake of improper mulching, to the detriment of the trees' health. Improper mulching can lead to root rot, inhibit the penetration of water and air, support weed growth, promote disease and insect infestations, and change soil pH. There are guidelines to follow to mulch your trees properly and avoid all of those problems. Follow these steps to mulch a tree that has never been mulched, and has grass growing beneath it:

• Using cardboard or newspaper, spread a layer over the lawn underneath the tree in a circle. Make sure that the layer of paper extends to the same distance the branches extend above.
• Wet the paper and cardboard until it is soft and pliable until it conforms to the contours of the ground.
• Add mulch to no more than three inches, adding a border of brick, stone, or synthetic liner to keep the mulch in place.

In order for the tree roots to get adequate moisture and air, never apply more than three inches of mulch. Do not pile mulch against a tree trunk, as the tree bark will rot because of the constant contact moisture. If you're mulching a tree that has previously been mulched, follow these guidelines to re-mulch:

• Check the mulch that is already in place and make sure that it is not more than three inches deep. Add or remove mulch accordingly.
• Rake and aerate the old mulch to break up matter sections and refresh the appearance.
• Pull the mulch away from the tree trunk several inches to expose the root crown and trunk.
• Ensure that the mulch extends to the length of the branches above.

You can choose from organic or inorganic mulches. Inorganic mulches are solids that never decompose, such as rock, lava stone, and shredded rubber. Organic mulches decompose and need to be replaced often, but their decomposition also helps improve soil structure and provide nutrients to the tree and surrounding lawn. Popular organic mulches include pine needles, wood chips, compost, and bark chips.