Landscape - How Plants Survive Prolonged Dry Weather

Plants have different mechanisms for surviving prolonged periods of dry weather. The following is some information on this topic from the University of Kentucky.

Plants Ability to Survive Prolonged Dry Weather

Plants generally fall into three categories relating to their capacity to get and conserve moisture:

• Water spenders use water freely but in deep soils have extensive root systems that absorb water from a large volume of soil. As long as some of their roots are in moist soil, they can survive. Many common landscape plants are of this type, e.g. black walnut, London plane tree, and mulberry.

• Drought evaders avoid water stress in several ways: they dry up or drop their leaves, sometimes they shed twigs and branches, or they become virtually dormant in dry weather. An example is the yellow-poplar, or tulip tree. While they have leaves, however, these plants usually transpire as rapidly as water spenders. Another excellent example of a drought evader is tall fescue. During a hot, dry summer, it turns brown while going dormant. After cooler, moist weather returns, fescue will green up and begin active growth again.

• Water conservers have ways of reducing water loss. Their leaves may be small, gray-colored, leathery, or arranged to reduce the amount of sunlight that strikes them. Their stomata may be structured to conserve moisture. Many plants from desert and Mediterranean climates are of this type. An example would be Yucca.

Adapted from "How Dry Seasons Affect Landscape Plants" by Mary L. Witt, Robert Geneve, John R. Hartman, Kenneth Wells, and Robert E. McNiel, University of Kentucky, Cooperative Extension.