The cumulative effects of dry conditions generally take several years to be visible in the plant.
Water stress affects most of the physiological processes associated with optimum plant growth.
Such stressed plants may look normal, but they are much more susceptible to attacks of insects and disease. In time smaller twigs and branches may decline, the foliage is smaller and overall growth will slow. Drought conditions are a serious problem for trees and many shrubs because a majority of their small, water absorbing roots are located in the top 6 inches of soil. These roots can extend outward about 3 to 4 times the distance from the trunk to the ends of the branches. The remaining roots are deeper in the soil and serve to anchor the plant.