Despite a relatively small amount of precipitation falling recently, the most recent U.S. Drought Monitor map indicates that much of Colorado is experiencing some level of drought. Trees in cities, towns and neighborhoods throughout our state are dormant now, but require occasional watering during dry winters to remain in top health.
Carrie Tomlinson, urban and community forestry manager for the Colorado State Forest Service, says planted trees in Colorado, especially at lower elevations, often require additional watering in the winter months during extended dry periods (e.g., more than two weeks without lasting snow cover).
“Making sure your trees receive adequate water throughout the winter and before irrigation is turned on for the year is necessary in Colorado, so they survive into the growing season,” Tomlinson said. “The moisture ideally comes from snow, but when it’s dry, we need to water the trees ourselves. On a warmer day—when temperatures are above about 40°F—use a hose to water slowly and deeply out to the tree’s dripline, so moisture reaches the roots. When you’re finished, disconnect the hose from the spigot and drain it completely so it doesn’t freeze and damage the hose or plumbing.”
Overly dry trees become susceptible to a host of health concerns, such as root and branch die-back, and then insect and disease problems.
Winter watering tips
- Water when it’s warm. The best time for winter watering is on days when snow has melted and the temperature is above 40 degrees F.
- Water a wide area. Tree root systems may spread much 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 drip or soaker hose on low setting, or soft spray wand, to apply water slowly to the full area at the rate of 10 gallons per inch of tree diameter.
- Mulch the tree. To retain soil moisture and save water, apply 4 inches of organic mulch onto bare soil within 2 to 3 feet from the base of the trunk, but not directly against the trunk.
- Repeat these watering tips as necessary. Until abundant spring precipitation arrives, be sure to continue watering every few weeks in the absence of snow.
Learn more about urban tree care.