In much of Colorado, winters can have extended warm, dry, windy spells. Warm winters without snow appeal to people, but cause winter drought. Trees and shrubs at risk from dry winters include recent transplants, evergreens and shallow rooted species such as lindens, birches, and Norway and silver maples.
Water plants when the leaves start to fall in the autumn to send them into winter with adequate soil moisture. For recent transplants, a soil needle can be used on low water pressure for one minute at each site to water the root ball and surrounding soil. Make injections in a grid pattern one foot apart and nine to 18 inches deep, using caution not to go below the absorbing roots.
Frog-eye type lawn sprinklers can be used to water established trees and shrubs. The most important area to water is from the edge of the branches halfway to the trunk, and the area two to three times that distance out from the edge of the branches. Allow sprinklers to run 30 minutes at each setting.
Monitor weather and soil conditions from November through March. Generally, if four weeks elapse without snow cover, water plants and trees again during these months when temperatures are above freezing and the soil is not frozen. Water plants early in the day so the water can soak into the ground before freezing nighttime temperatures.
Remember to disconnect and drain hoses after use. Don’t activate sprinkler systems during the winter.
For more information, see the following Colorado State University Extension fact sheet(s).
For more information, see the following Planttalk Colorado™ script(s).