Abstract

KOCH, JERRY. 1984. Watering trees: when, how, and how much? Am. Forests 90(7): 13-16.

Trees need water, especially during the first three to four years after planting when they are most susceptible to drought conditions. Water is one of the most important factors needed for proper tree growth and the one most often neglected when it is in short supply. A large shade tree is capable of transpiring several hundred gallons of water through its leaves on a hot day. Determining when to water, the best method to use, and how much water to give a tree is not always easy. To get an indication of water stress, examine the soil around the tree. Since the majority of the tree’s roots are in the upper 12 inches of soil, taking a sample of the soil in the area will tell the story. By squeezing a handful of the soil sample, you will be able to tell whether the soil needs additional water. No matter what soil type you have, it is far better to give the soil around the tree a good soaking at less frequent intervals than to water just a little every few days. There are two common methods of watering trees. One is surface watering. Another method—subsurface watering-can be done with a root feeder. In areas of the country where rainfall is generally common in the summer months, watering trees is not an expensive maintenance item since it has to be performed only periodically during occasional dry spells.

• © 1985, International Society of Arboriculture. All rights reserved.