Winter can be beautiful and offers us entirely different ways to experience our landscapes. Winter activities and opportunities are a big reason I stay in Colorado and why so many people end up relocating here. So, while you’re taking a break from skiing, boarding, or shoeing, remember that winter moisture is important to your landscape plantings, especially new landscape plantings.
We’ve experienced a dry fall, and so far this winter has provided little precipitation along the Front Range; which means it’s time to provide some water to shrubs and trees. Why? Plants are indeed dormant during winter but still need to absorb moisture to offset their moisture losses. Along the Front Range our dry warm spells and windy days during winter months can dry out plants and soil. Winter burn or desiccation can be a real threat to the health of trees and woody shrubs. Simply put, desiccation is the drying out of a living organism; the organism loses moisture faster than it can be absorbed. Broad leaf evergreens like grape holly and boxwoods are more susceptible, and in my experience arborvitae and pines as well. Most trees and shrubs will benifit from additional moisture in the winter.
If around 2” precipitation has occurred in the last 30 days it is not necessary to water. Remember, two inches of snow does not equal two inches of precipitation, not even close. Instead of guessing about precipitation totals you can go to https://www.crh.noaa.gov/bou/?n=climo for Denver’s information and be sure.
November through March are the months to consider watering. Winter watering is most effective when temperatures are above 40 degrees F during the day and when the ground is not frozen solid. CSU Extension Service’s fact sheet number 7.211 is a great source for specific information about winter watering.
When there is a warm spell at my own garden, I turn the spigot on so that a slow trickle of water is flowing from the end of the hose and let it soak in next to a shrub or tree for 30 to 45 minutes, not very scientific but it is easy and successful. When watering larger trees, I’ll move the hose around to several locations underneath its canopy. Don’t forget to detach your hose from the spigot after finishing. You can always arrange for a tree service company to provide winter watering for your landscape and most will give you a set monthly price for this task.
The most important aspect of all this is to remember winter moisture is vital to newly planted trees and shrubs. Without it, these plants will not have a good chance to establish and thrive. Trees and shrubs can take several years to establish themselves and winter moisture levels should stay consistent through the first few years after planting.