1 - Proper plant selection, planting, and care can minimize tree problems.

Yard and Garden May 3, 2014

Q.

I have a large Bradford pear tree that shows beautifully in the spring and fall, it is about 15 to 20 feet tall. Several branches have broken off in the high winds. I also have some patio and wall damage from the tree roots; they are about 10 feet away from the tree. I suspect my best approach is to replace it. But I do not know the best tree to replace it with. Or maybe it could prune the roots and hope for the best. How about an Oak as a replacement? Any ideas would be very helpful.

-Leroy G.

Alameda, NM

A.

Bradford pear trees can be beautiful, but as you are experiencing, they can be damaged by wind and ice when they become large. This is a result of the branching habit of the Bradford pear tree. Are you sure the damage to the patio and wall are due to the pear tree? It is possible that the pear is the culprit, but other nearby trees may be involved in causing the problems.

The root damage to patios, walls, and paved areas can be caused by almost any nearby tree or by a replacement tree, but the larger the tree, the greater the potential for root damage. Irrigation and soil preparation techniques can also increase or decrease damage by roots. Management techniques that encourage deeper rooting will help reduce root damage, but may not eliminate it.

Smaller trees such as redbuds, hawthorns, desert willows, and similar trees may cause fewer problems due to their roots. Smaller stature trees have smaller root systems. If you can plant the trees farther from patios and walls, then oaks and Chinese pistache trees may be good choices for replacement. They are good shade trees and some may give excellent autumn color. These trees can cause fewer problems for patios and walls because of the nature of their root systems compared to other large trees such as cottonwood trees. However, any tree can be problems for septic systems and other utilities if planted too close to these utilities because of their deep roots systems.

To maximize good root growth and minimize root problems, proper soil preparation, loosening soil deeply (1 foot or more) over a large area before planting the tree will help the tree utilize deeper levels of the soil. When planted in compacted soils, tree roots will tend to grow on the surface and damage patios and walls. Tree roots need oxygen in the soil, and compacted soil have little pore space for oxygen and also resists water infiltration to deeper levels. These factors force roots to grow on the surface of the soil. Irrigation that moistens deeply (2 to 3 feet) with surface drying between irrigations will also encourage deeper roots. Mulch over the root area will also help by keeping the soil moist, conserving water, and reducing re-compaction of the soil.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

Links:

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