This winter has brought very little moisture in the form of rain or snow. With little moisture and unseasonably warm temperatures following last winter’s short snowpack and little rain over the summer, Moffat County plants are thirsty and drought-stressed. Under these conditions, winter watering is crucial. During winter, many trees and shrubs still require hydration even when dormant.

Winters in Colorado often bring strong winds, dry air, fluctuating temperatures and occasional snowless periods. These conditions, combined with limited summer rainfall, can quickly deplete subsurface soil moisture. Without additional watering, especially during droughts, trees, shrubs, grasses and perennials can suffer damage.

Signs of drought stress may not be immediately visible, but a weakened immune system can lead to a whole host of problems later on. Often, symptoms of stress appear in late spring or early summer and can include plant death, wilting, leaf or needle loss, disease, insect damage and overall, a decline in plant vigor. Evergreen trees may exhibit needle browning or branch dieback. Plants that are not fully established or have shallow roots are more vulnerable to winter damage. During winter, roots remain active, providing nutrients to the tree, while the above-ground portion is dormant.

Snow typically provides about one inch of water per foot, which is often insufficient for trees throughout the winter. Monitor snowfall; if four weeks pass without snow cover, water those plants. The best time to water is when the air and soil temperatures are above 40 degrees Fahrenheit, after leaves have started to fall. This can continue through March. 

The best time to water is mid-day, allowing extra time for the water to soak into the ground before a night freeze. A slow, steady soak works best with a drip or soaker hose. Water should be applied under the branches, extending to the tree’s dripline. A simple guideline for how much water a tree needs is that for each inch of tree trunk diameter, the tree needs about 10 gallons of water, reaching a depth of approximately 12 inches. For example, a tree with a 2-inch trunk diameter should receive 20 gallons. 

Organic mulch, made of materials like wood chips or straw, helps retain ground moisture. Apply mulch about 3-4 inches deep around trees or shrubs. Avoid piling mulch against the tree trunk; leave a space of 1-3 inches. Newly planted trees, shrubs, and grasses may need extra water, so watch them closely. Established trees have mature root systems and are better at withstanding drought stress.  

Plant placement can also cause a plant to require additional watering. Plants situated near buildings, walls, or fences may receive reflected heat. Those placed on the west- or south-facing sides of a building or wall will get direct winter sun exposure and are vulnerable to strong wind damage. Consequently, leaf, needle, and soil moisture will dry out more quickly. Monitor plants, soil, and weather conditions, and water once or twice a month if dry conditions persist for more than 4 weeks.

For more information and resources, contact the Moffat County Extension Office. Additionally, online resources can be found by visiting extension.colostate.edu and searching Winter Watering factsheets. Or visit planttalk.colostate.edu.  

Megan Stetson is the Moffat County Extension Director.