Extension

Although they aren’t the most visible part of the tree, the roots are the true heroes in the world of horticulture. Sprawling beneath the soil’s surface, tree roots have different jobs, including drawing up water to provide a drink and giving stability against environmental forces. They perform complete biological and physical functions and play a vital role in a tree’s health and longevity.

One common problem with landscape trees is the development of circling roots around the trunk. The roots can cause girdling, which restricts the movement of water and nutrients throughout the tree. The good news is that gardeners can discourage circling roots with proper tree planting and care.

The first step is to plant trees to the correct depth so that the root flare of the trunk is visible. The root flare is the area where the roots and trunk meet, forming a slight widening of the trunk. When planting, be careful not to pile too much soil or mulch against the base of the tree. While mulch is purposeful, it is often misused. Keep the donut method in mind when distributing mulch. Donuts have holes in the center, and so should the ring of mulch around the tree. When too much mulch is piled up against the trunk, it encourages circling roots, especially in newly planted trees.

Another tip is to perform regular maintenance of the root collar area. On an annual basis, remove the accumulated mulch and soil. If done regularly, this can be accomplished with a broom. If not done regularly, the soil and mulch can become compacted, making them harder to remove.

Typically, a tree needs about 1 to 3 inches of mulch. Too much mulch prevents necessary oxygen from reaching the roots. Plus, as mulch decomposes, it becomes soil. Applying mulch year after year without cleaning the root collar can lead to soil accumulation around the roots.

Check for roots circling the trunk about every three to four years. Using a hand trowel, remove the soil and mulch from around the base of the tree until the first set of roots is visible. Remove tiny roots by cutting them away with hand pruners. If larger encircling roots are discovered, consult the local Oklahoma State University Extension office or call an arborist regarding treatment.

The chances of correcting the problem and saving the tree are higher if the issue is detected early.