Healthy plants start with a healthy root system. This is easy to appreciate when you are first purchasing plants and are able to examine the roots, but what about when it is growing in the ground? Read on to learn more about these very important structures.
Surprising to many people is the fact that most Florida trees do not have tap roots. Our very shallow water table and compacted soils in urban areas mean that most tree roots are in the top 3-6” of soil. Picture the flat pancake of soil that is commonly seen when a tree falls. Keep this in mind when you consider digging under or near a tree because the fine roots will make this job very difficult.
Frequently, roots extend from the trunk as far as the tree is tall. Roots on trees and shrubs planted in a landscape grow to 3 times the branch spread within a few years. Keep this in mind when you are considering digging or even parking vehicles close to this area. Damaging roots on one side of a tree can cause branches to die back on that side or throughout the canopy.
Roots need to breath. Have the roots of your tree gotten in the way of your lawn mower? Some trees, such as Bald Cypress, are known for growing roots that stick up out of the soil. These are known as “knees” and studies report that they serve to supply oxygen to the roots of the trees. The knees are a part of the root system, which grows above the soil so it serves an important function. Cutting off knees or any root is discouraged because it creates an open wound on the plant that is more prone to disease issues. If roots are getting in your way consider removing the turf and simply mulching the area in question.
Palm roots are unique. Palm roots emerge from the base of the trunk only, not from other larger roots. These roots grow in length, but do not increase in diameter. Have you ever noticed where a large tree has cause a sidewalk or driveway to crack and rise? Palm roots will not do this because they do not get wider, only longer as they grow. Palms might be worth considering for tight places where there are concerns about cracks.
Planting trees at the proper depth is the best way to help them grow a healthy roots system. Cut any circling roots growing up above the topmost root. This will prevent these roots from strangling the trunk in the future. When you are planting, it helps to leave the new plant 1-2” above the ground. As the soil settles, this will leave your tree at the right depth.
When you are planting flowers and shrubs, it won’t hurt anything to break apart the roots in a new plant. These are not as concerning as the roots of a tree however, because they will not reach the size and cause the potential damage in the same way. Spreading these out will help your new plant to establish well and reward you with a beautiful landscape.