Extension Spotlight

Trees and shrubs still require water during fall and winter. According to the Arbor Day Foundation, soil that stays most stays warmer in the fall and winter. If the trees and shrubs have cells filled with water, then this helps protect them from winter damage. This condition is called turgid.

The best practice for watering is to let the water soak in the soil slowly. Trees uptake soil better with that type of condition. Be sure to soak the top 12 inches. Keep watering on a regular basis until the ground freezes. Once the ground freezes, if there is no snow cover of any significance, then start watering when the temperature is 40 or above — so the water gets to soak in slowly, again. With well-established trees, water every four to six weeks, if there is no snow cover.

According to Colorado State University, Jim Klett, watering for newly established trees is slightly different. You must know the diameter of the tree. For every inch of trunk diameter, it takes the same number of years to establish or more. If your tree is three inches in diameter, then it will take three years to establish. Newly established trees that are not well watered can sustain damage in winter drought weather. Watering every two weeks in the winter on newly established trees is needed if there is no snow cover.

Cold, dry winter winds remove water from the tree needles faster than their roots can absorb water according to the Arbor Day Foundation. Plants in southwest exposures are prone to utilizing more water during the winter along with windy locations. Having trees or other plants with dry roots before entering winter will succumb to harsh winter conditions and may not leaf out in spring or if they do struggle to survive.

If you need to check the moisture level in the soil, use a soil probe out by the dripline or use a trowel that you place in the soil in the top two or three inches and move it back and forth to create a trench. Place a finger in the trench to test to see if there is moisture. Then water accordingly.