Drought Tolerant Trees

Wayne K. Clatterbuck Associate Professor Forestry, Wildlife & Fisheries University of Tennessee

Introduction

Late-season droughts are common in many Texas landscapes. Many trees are stressed by prolonged periods of hot, dry weather. Selecting trees that use water efficiently without the need for frequent watering or irrigation is one way to make your landscape more resistant to droughts. With impending water shortages in many urban areas leading to prohibitions of irrigation or watering, planting trees that are more tolerant to drought conditions is the best long-term solution to a healthier, low-maintenance landscape.

Thick leaf waxes of Eastern red cedar foliage assist in its drought tolerance.

Thick leaf waxes of Eastern red cedar foliage assist in its drought tolerance.

A few of the factors to consider when selecting trees that use water efficiently are:

  • Native trees are better adapted to local soil, moisture, climate and pest conditions than non-native trees.
  • Trees with small leaves are more easily cooled and have better water-use efficiency than trees with larger leaves.
  • Upland species are usually more drought-resistant than bottomland species.
  • Early successional species, those that colonize old fields and disturbed sites, use water more effectively than late successional species.
  • Trees with deep, upright crowns are more effective in water use than those with flat, wide-spreading crowns.
  • Trees with multilayered crowns having many living branches and leaf layers are more water-efficient than those trees with leaf canopies that concentrate leaves in single layers along the outer edge of the crown.
  • Drought-tolerant plants usually have thick leaf waxes and bark, efficient stomatal control, and extensive root systems.

Although there is not an ideal drought-resistant tree for every landscape, many trees have drought-resistant features and are more tolerant of dry conditions than others.  For more information on selecting a tree, check the Texas Forest Service tree-planting guide at http://texastreeplanting.tamu.edu. However, as with any new planting, they will need to be watered until they are established.

References

Coder, Kim D. 1999. Tree selection for drought resistance. The University of Georgia, Warnell School of Forest Resources, Athens GA. 4 p