As I write this article, the temperature in Pagosa Springs is a balmy 47 degrees F. Pagosa Weather reports on pagosaweather.org that there has not been any measurable precipitation since Dec. 4.
According to Arleen Prochazka, the first few days of the month we had an average of .62 inches of moisture and 8.4 inches of snow in Pagosa Country.
Their forecast highlights state that a “giant, blocking, evil ridge is forcing the storm to track well to our north. Through December 24th we will have lots of sun and above average temps.”
That leaves us with three weeks of dry weather. They also share that the best chance for precipitation is Dec. 25-27. I know we are all hoping for snow.
The truth is dry air, low precipitation, little soil moisture and warmer temperatures are often characteristics of our winter weather in southwest Colorado.
The result of warm, dry periods during the winter can cause injury or death on your trees and shrubs. Affected plants may appear perfectly normal and resume growth in the spring using stored food energy, but they may be weakened and all or parts of the plant may die by late spring or summer when temperatures rise.
Woody plants with shallow root systems require supplemental watering during extended dry periods. Newly planted trees are most susceptible to winter drought injury. Trees generally take one year to establish for each inch of trunk diameter. For example, a 2-inch diameter tree takes a minimum of two years to establish under normal conditions.
Water only when the air temperatures are above 40 degrees F. Apply water late morning or by mid-day so it will have enough time to soak in before possible freezing at night. You do not want ice to form around your plants or on your grass. A solid layer of ice on lawns persisting for more than a month can cause suffocation or result in matting of the grass.
Monitor weather conditions and water one or two times per month during extended dry periods without snow cover. Plants located on the south and west sides and in windy sites may require additional water.
Trees obtain water best when the water can soak into the soil slowly to a depth of 12 inches. As a general rule, apply 10 gallons of water to each diameter inch of tree. For example, a 2-inch diameter tree needs 20 gallons per watering. Use a ruler to measure your tree’s diameter at 6 inches above the ground level.
During dry winters, all shrubs benefit from watering. Apply 5 gallons of water two times per month for a newly planted shrub. Small established shrubs should receive 5 gallons monthly. Large established shrubs (more than 6 feet tall) require up to 18 gallons of water on a monthly basis. Decrease amounts of water to account for precipitation.
Woody plants and shrubs benefit greatly from mulch in the winter to conserve soil moisture and protect exposed roots from cold and drying. Mulch can also minimize soil compaction and manage weeds.
Apply mulch to a depth of 3 to 4 inches; too much mulch can weaken trees and shrubs, and prevent water and air from reaching the soil.
When you have questions, Colorado State University (CSU) Extension has research-based answers.
Contact your Archuleta CSU Extension Office to learn more about winter watering and gardening in the southwest at (970) 264-5931 or https://archuleta.extension.colostate.edu.
Resources:
• Klett, J.E. Cox, R. Fall and Winter Watering Fact Sheet No. 7.211. Colorado State University Extension, January 2004, reviewed March 2013.
• Hammond, Eric. Whiting, David. Wilson, Carl. Moravec, Catherine. Reeder, Jean. Mulching. Colorado State University Extension, December 2015, reviewed April 2023. https://extension.colostate.edu/resource/mulching/.to register.
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