How to Water Trees and Shrubs

When watering trees and shrubs, keep in mind that a slow soaking is more effective than a lot of water at once. This slow release allows the water to be absorbed into the root zone. Water outside of this area will not be taken in by the tree.

Deep watering trees and shrubs leads to deep roots. Strong root systems help trees and shrubs handle storms, winds, extreme temperatures, drought and disease. In general, deep watering means to penetrate the soil to a depth of 12 to 14 inches.

As you figure out how to water trees and shrubs, learn the term “drip line.” The canopy of a tree or shrub sheds water in a perimeter that is known as the drip line. The plant’s strongest feeder roots soak up water in this area. When you water, stick to the drip line and not the trunk of the tree. Remember that as plants grow, the drip line expands.

Drip irrigation systems are convenient for deep watering trees and shrubs. Soaker hoses and sprinklers on hose timers are efficient as well. For deep watering, keep the water trained on the trees and shrubs, and not turf.

The amount of time to water depends on many factors such as the irrigation system you use, root zone depth and the type of soil (sandy, loamy, clay). Weather is a factor, too. If it’s a dry winter, the rule of thumb is to water after 6 weeks of no precipitation. Water when the weather is cool and not freezing.

To determine soil type, try the squeeze test. Dig down at least 4 inches and gather a handful of soil. Sandy and loamy soils will feel dry. Clay soils will be hard to break apart. Water travels fastest through sandy soil, clay soils are difficult for water to infiltrate.

During your fall gardening chores, remember to water trees and shrubs. Newly planted trees and shrubs usually get a thorough soaking when they go in the ground and a few weeks afterward.

Pay attention to older established trees and shrubs during the fall. Nurture them before winter sets in, especially if your area has been affected by drought conditions. Trees and shrubs need water to flourish and to withstand the elements.

• Newly planted trees and shrubs should be watered about once a week until they’re established. After they mature, let them go without water for longer periods, to build up drought resistance.
• A layer of mulch cools the soil, retains water and eliminates weeds that compete for water and nutrients. Do not pile mulch against trees in a “volcano,” which can lead to girdling roots and problems with pests. Instead, create open “craters” at a depth of no more than 4 inches.
• Save on your water bill by capturing rainwater in a rain barrel and using it to deeply water trees and shrubs.
• Mornings are best for watering. Cool nighttime temps encourage mildew.

A variety of conditions can stress plants, including drought, a location with too much sun, or even too little sun. Problems with soil and drainage can affect plants, too. These conditions give pests and diseases opportunity to damage trees and shrubs.

Signs of drought stress include wilted or yellowing leaves. In deciduous trees and shrubs, fall coloring may come early, and you may notice leaves that look scorched, are undersized or off-color. Evergreens will lose their healthy green color and may drop needles.