Tree Roots in Lawn

Raised Tree roots in a yard.

This is one of the most often asked questions I get in this heavy clay soil area.

What causes raised tree roots?
Trees need air space called macro pores in the soil or they suffocate. Heavy soils such as clay have less macro pores. Macro pores are created when organic material breaks down actually leaving an air space. So if the tree is growing in a soil without enough oxygen, it will push up the roots looking for that air space.

Water will fill this air space. So if you water too much, the tree will again, push it's roots upwards seeking a better environment that it can survive in.

How do we fix raised tree roots?
Well we do not cut the root unless there is no other alternative. There are five main scaffolding roots the tree is using to support itself and to gather nutrients. If you cut one of these it would be like your diet being cut by 20% and your leg being cut off below the knee.

There are two good ways to properly take care of raised roots.

1. Amend the soil with organic material. The best way to do this is with the air spade we talked about in the earlier blog. This breaks up the soil and allows you to amend it with more organic material. This should be done by a professional ISA Arborist who has been trained in this specific work. A tree well, as wide as the drip line, is ideal although not often practical. This area can be covered in mulch. The best mulch is ground leaves which is what the tree would indigenously use.

2. The second option is to put a mixture of organic material like a leaf mulch or well composted material, in with a sand mixture, and cover the roots with an inch at a time. The grass will grow through this material well and actually thrive in it. Every few months add an extra inch until the root is completely covered.

Be sure to adjust your watering habits. Check the tree moisture within the drip line. This is best done with a water meter. The cheaper meters will work fairly well and be better than nothing at all. The tree should be wet once a week, and to the middle of dry on the meter, once a week, at least 6 to 8 inches down. If it is pegged wet all week, you need to adjust your watering.

Do not run over these roots with the lawn mower and scalp them. This allows disease and bacteria into the root system which can eventually kill a tree. If you've done this, leave it exposed and allow the tree to heal itself by compartmentalizing the wound. That is that rolled up look you see on old wounds. Once it has done that, use one of the above methods to cover the root so it doesn't happen again.

Root care is the foundation of the tree's health. Good link for Tree Root basics.