Colorado weather can turn on a dime, so don’t let a warm fall lull you into neglecting your landscape’s winter needs. Trees react naturally to shorter daylight hours and lower temperatures by “hardening off.” A sudden temperature drop can catch them unprepared, especially younger trees with less developed root systems and lots of delicate new growth. Even established trees can use a little extra help to make it through Colorado’s harsh winters.
Here are some things to do for your trees before the first hard freeze sets in.
Stop Fertilizing and Cut Back Watering
Stopping fertilization and cutting back on watering will help your trees harden off for the winter. But don’t eliminate watering altogether (see below).
Use a Trunk Wrap on Delicate Trees
Trees with thin bark, especially younger ones, are subject to frost cracks and sun scald from the extreme temperature fluctuations and harsh winter sun in Colorado. Give the youngsters extra protection by wrapping their trunks with a commercial tree wrap. Start from just above the ground and wrap upward to the first branches to avoid trapping moisture and leave the wrap in place until mid-spring.
Mulch the Tree Base
Lay down 2-4 inches of wood chips, bark, or other organic mulch starting from just off the trunk out to a couple of feet to insulate the roots, improve water absorption, and cut down evaporation from the soil. Your community may offer recycled mulch for free, or you can buy it at nurseries and home centers.
Prune Only as Needed
Pruning is best done once a tree has gone dormant. That way sap loss is avoided and wounds are less likely to become infected or infested. Late winter is best, but dead branches can be removed and light shaping can be done any time the tree is dormant.
Don’t Forget to Water
Colorado’s climate is dry to start with and winter is no different. Snow can evaporate before melting in our thin dry air (called sublimation), so give your trees an occasional drink throughout the winter when there’s been no significant snow for a 2-3-week period.Water slowly from the tree’s base to its drip line, about 10 gallons for each inch of trunk diameter. Warm days above 40° when the snow has melted are best for absorption into the soil.
If you need maintenance of any existing trees or shrubbery, Donovan Arborists offers planting, pruning, and shearing and insect and disease management services in the Denver area. We’re happy to give free estimates to homeowners and property managers for any services they may need.
