Tips for watering trees during drought


By Ryan Lockwood

Special to The SUN

Despite heavy rains over parts of Colorado in recent months, persistent drought conditions have parched the soil over much of the state, stressing even irrigated lawns and urban landscape trees. During these periods of drought, homeowners should consider supplemental watering to keep their trees healthy.

“Adequately watering your trees is the best way to ensure optimum growth and vigor during the summer months,” said Keith Wood, community forestry program manager for the Colorado State Forest Service. “Dry trees become susceptible to root and branch die-back and subsequent insect and disease problems.”

The most recent U.S. Drought Monitor map, released last week, indicates that approximately 50 percent of Colorado is currently experiencing some form of drought — with some southern portions of the state under “severe” or worse drought classifications.

The CSFS offers the following tips to keep trees healthy during summer drought:

• Water a wide area. Tree root systems, unlike carrots, may spread two to three times wider than the height of the tree, with most absorbing roots in the top foot of soil. Apply water to soak the entire area underneath the full span of a tree’s branches.

• Water slowly. To ensure deep penetration, use a deep root fork (inserted 8 inches or less), soaker hose on low setting or soft spray wand to apply water slowly to the full area.

• Keep the yard green. Trees located in irrigated lawns generally do not require additional water, as long as the area surrounding the tree receives adequate moisture. Conversely, a dry, yellow yard means the roots of any trees present are also dry.

• Focus on non-irrigated trees. Trees that do not receive water from sprinkler systems or irrigation require additional water. Every week, apply 10 gallons of water for each inch of tree trunk diameter. Water newly planted trees even more frequently; larger trees, which have extensive root systems, can be watered less frequently.

• Mulch. Mulch is an inexpensive solution to retain soil moisture and save water. Apply 4 inches of organic mulch onto bare soil within 2 to 3 feet of the base of the trunk (removing any grass first, if necessary). Do not allow the mulch to directly contact the trunk.