Palm Roots Less Likely to Damage

Q. We have a large Mexican fan Palm in our courtyard which is now about 15 feet tall. About 5 to 6 feet from the tree is a “Pebblestone” plastic divider which is slightly raised. The Pebblestone representative said it is likely root problems from the palm tree. A gardening company told me the palm tree roots are not likely the problem. Which is it?

A number of people asked me about the damage from Palm roots two different types of hardscapes. Here is the skinny on this topic. This picture is not from the reader but someone else.

A. Palms are a different type of plant altogether from ornamental trees. They are monocots while most ornamental trees are dicots. The internal physiology and anatomy is very different between the two.

Palm trunks are much different from the trunks of other types of trees. It's full of these long fibers. The inside is more similar to the inside of a grass plant on steroids.

            Palm trees grow differently and have roots that are very different from ornamental trees.

Basically, palm roots grow closer to the trunk while ornamental tree roots can, if water is available, grow a distance horizontally twice their vertical height.

In Las Vegas resident asked me to intercede regarding the claim by an HOA that palm tree roots were damaging a wall that needed to be repaired. As you can see, this palm tree was growing right next to the wall and causing very little damage, if any. That's the good news. The bad news, oleanders growing in the same area were probably the culprit.

            Ornamental tree roots are larger in diameter closer to the trunk and smaller in diameter with more distance from the trunk. Palm tree roots don’t get bigger with length as like ornamental tree roots. Palm tree roots don’t increase much in diameter their entire length.

Many tree roots increase in diameter as they grow away from the trunk of the tree. Palm roots, more similar to grass roots than tree roots, do not.

          This increase in diameter of ornamental tree roots is very powerful. Heaving of sidewalks, patios, driveways, foundations, footers of walls are frequently caused by ornamental tree roots increasing in diameter if planted too close to them.

            Water and where it is applied also controls where roots grow in desert soils. If you want plant roots to grow in a specific direction and not another, apply water to the soil where you want roots to grow.

            I would not plant palms closer than 4 feet from anything that might be damaged. Apply water in the area where you want root growth. Do not apply it close to other areas where damage could result.

            Installing root barriers to add more protection to these areas is another option.