Getting to the Root of How to Water Trees

29 August 2011

This is the VOA Special English Agriculture Report.

Some trees can survive a long time without water. Think of trees that grow in the desert. But other trees may need more moisture than they can get from rainfall or from the air -- from, say, coastal or mountain fog.

The soil stores moisture during cooler weather. But most of that moisture is gone by the middle or end of the hottest months of the year.

A white pine tree in Bradford, New Hampshire

Trees and other plants can look thirsty. Leaves can become droopy and hang downward. They can also turn yellow. Yellowing can be a sign of too much water. But it can also be a warning sign of too little water.

The Vacaville Tree Foundation is a volunteer community group in California. It has advice for watering newly planted trees and established trees.

With a newly planted tree, the roots have not yet spread out from the root ball. The root ball can become dry faster than the dirt around it. So put water on the area of the root ball and the surrounding soil until the roots become established.

Once a tree is well established, water deeply instead of often. The amount of water needed depends on the tree and the soil. Clay soils hold water for longer periods while sandy soils hold less water. During the hottest season, a deep watering may satisfy a tree for anywhere from ten days to four weeks.