Colorado is a high desert and is known for dry air, low precipitation and low soil moisture content. This combined with the constantly changing temperatures are characteristics of fall and winter here and these contribute to the dry conditions. In Boulder and surrounding areas in the foothills and plains to the east often have little or no snow cover to provide soil moisture from October through March. This leaves trees, shrubs, perennials and lawns vulnerable, under these conditions plant life may be damaged if they do not receive supplemental water, thus the need for winter watering.
The result of these long, dry periods during fall and winter can be injury or death to parts of plant root systems. Plants may appear perfectly normal and resume growth in the spring using stored food energy but some plants can be weakened and all or parts of them may die in late spring or summer when temperatures rise and their root systems have been compromised. Weakened plants are also vulnerable to insect and disease problems that can spread to other healthy plants and trees.
Winter watering may only be done when air temperatures are above 40 degrees F, fortunately there are more than enough days that meet these conditions to apply the tree service in Boulder. We make sure to water during the height of the day so the water will have time to soak in to the ground before a possible freezing at night if temperatures do go beneath 32 degrees.
Evergreen trees and shrubs will suffer the most as they can still transpire moisture through their needles/leaves unlike a deciduous tree or shrub that lost all their leaves. Even though the ground may be frozen they can still dry out. To prevent this mist their needles two to three times per month. Try to imitate a slow soaking rain and move back and forth many times to really soak them. Only water the soil if the ground is not frozen. A deep root “Watering Spike” is best to use for this application.
Newly planted trees are especially susceptible to winter drought injury. Take special care with trees that have less than a two-inch diameter trunk. Planting trees can be expensive so protecting your investment can save you money.