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Your sprinklers are off. Does your landscape still need water?
Yes. Sometimes.
That answer surprises a lot of Colorado homeowners, and winter landscape care is more important than you might realize.
When the sprinkler system is winterized, it is tempting to assume that the landscape is finished needing water until spring. But Colorado winters can be surprisingly dry. Snow is not always consistent, and long stretches of sunny, windy weather can pull moisture from the soil.
And that’s in a normal winter. Last winter, 2025-26, was one of the warmest, driest and least snowy winter seasons since record keeping began in the late 1800s. Most of the 2026 summer season has provided little relief. Although monsoons did finally kick in, they didn’t do much to replenish Denver’s stored water deficit. We’re all hoping for more winter moisture, in the form of snow, but there’s no guarantee, so your landscape may need supplemental water through the winter.
That is where winter watering comes in as part of winter landscape care.
Colorado State University Extension recommends supplemental watering during prolonged dry fall and winter periods because extended dryness can damage plant roots.
The trick is knowing when your landscape actually needs water and how to provide it without turning your sprinkler system back on.
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A practical place to start is this:
Has your landscape gone about three weeks without significant precipitation?
If no, you probably don’t need to water.
If yes, take a closer look.
Denver Water specifically recommends winter watering during dry stretches of about three weeks without significant precipitation. That does not mean every plant automatically needs a drink every three weeks. It means three weeks without meaningful precipitation is a good signal to inspect the landscape rather than simply assuming everything is fine.
Do you need help making a plan for winter watering?
Before you water, check three things:
Winter watering should happen only when conditions are appropriate.
1. Is the temperature above 40°F?
Otherwise, wait for a relatively warm day.
2. Is the ground frozen?
Frozen soil cannot absorb water effectively.
3. Is there snow covering the ground?
If there is a persistent layer of snow, you generally do not need to add water.
CSU Extension recommends watering when air and soil temperatures are above 40°F and there is no snow cover. Water around midday so the moisture has time to soak into the soil before nighttime temperatures drop.
Not every plant has the same needs.
During a dry winter, pay particular attention to:
- Newly planted trees
- Young shrubs
- Recently planted perennials
- Evergreens
- Plants on exposed south or west-facing sites
- Plants in windy locations
- Plants near walls or other surfaces that reflect heat
- Plants growing in restricted or compacted root zones, like planters, or the space between the sidewalk and the curb.
Newly planted trees deserve particular attention. Their root systems are still developing, so they have less access to moisture than established trees. Most evergreens can also benefit from supplemental water during winter dry spells because they retain their foliage and continue losing moisture.
What about established trees?
Established trees are tougher, but they are not invincible.
A mature tree with a large, healthy root system can tolerate dry conditions better than a newly planted tree. But prolonged winter drought can still cause stress and root damage.
CSU Extension recommends winter watering of trees and woody plants when natural precipitation remains low. Their guidance suggests watering about once or twice a month during dry winter conditions. Denver Water similarly recommends watering trees during prolonged dry periods, applying approximately 10 gallons for each inch of trunk diameter.
Where should you put the water?
Don’t simply dump water at the base of the trunk.
The most important area is the root zone, especially around the dripline. The dripline is roughly the outer edge of the tree’s branches. For a mature tree, roots can extend well beyond that area, but the dripline provides a useful starting point.
Water slowly enough that it can soak into the soil rather than running across the surface.
Denver Water recommends watering deeply enough to moisten the soil in the critical root zone and notes that most absorbing tree roots are in the upper 12 inches of soil.
What about shrubs?
Shrubs need less water than large trees, but they can still suffer during a dry winter.
Denver Water’s current winter guidance gives a general range of 5 to 18 gallons for shrubs, depending on size. CSU Extension provides similar guidance and emphasizes that newly planted shrubs require more attention than established shrubs.
Again, these are guidelines, not instructions to blindly pour a particular amount of water onto every shrub. Soil type, plant size, exposure and recent precipitation all matter.
Mulch helps
A layer of mulch can reduce moisture loss and help moderate soil temperatures. Apply mulch beneath the plant’s canopy, but keep it away from direct contact with the trunk or base of the plant. For trees, Denver Water recommends approximately 3 to 4 inches of mulch within the dripline, leaving space around the trunk.
Don't turn the sprinkler system back on!
This is probably the most important point.
Winter landscape care does not mean restarting your irrigation system.
After a proper sprinkler blowout, the system should remain off for the winter.
If an individual tree or shrub needs water, use a hand-held hose, soaker hose or another appropriate low-volume method.
This is especially important under the drought restrictions taking effect October 1, 2026. Denver Water prohibits spray irrigation of trees, shrubs and perennials after September 30, while allowing hand watering with an automatic shutoff nozzle or qualifying low-volume, non-spray irrigation.
Winter watering decision guide
Has it been about three weeks since significant precipitation?
→ No: Don’t water yet. Keep monitoring.
→ Yes: Continue to evaluate.
Is the ground frozen or covered with snow?
→ Yes: Wait.
→ No: Continue to evaluate.
Is the temperature above 40°F?
→ No: Wait for a warmer day.
→ Yes: Continue to evaluate.
Are there young trees, new shrubs, evergreens or plants in exposed locations?
→ Yes: Give those plants priority.
→ No: Check established plants for signs of prolonged dryness.
Winter watering is not about keeping everything wet all winter. It is about preventing long periods of severe dryness from damaging the plants you have invested time and money to grow. And not every tree or shrub has the same requirements.
That is the subject of our next article: Do Trees Need Water in Winter? How Plant Age, Species and Location Change the Answer.
Wintering Watering Methods
Below are several options—listed in no particular order—to help your trees and plants get through another dry, warm season:
- Buckets: Purchase multiple 5-gallon buckets from a hardware store. Drill four evenly spaced ½-inch holes around the bottom. Place the bucket on the tree or shrub’s dripline and fill it with water. Allow it to drain slowly into the root zone. Once empty, move the bucket one quarter of the way around the tree and repeat.
Completing four placements provides thorough saturation. With multiple buckets, you can water several plants at once. - Soaker Hose: Available at Amazon, Home Depot, Lowe’s, and most hardware stores, soaker hoses come in various lengths and connect directly to a garden hose.
Lay them around trees, shrubs, or garden beds. Tiny perforations allow water to seep out slowly along the entire hose. They can remain in place through winter and be connected only when needed. In spring, simply remove and store them. Soaker hoses are often more convenient and efficient than buckets for watering multiple plants. Pricing varies by store. - Deep Root Watering Probe: A deep-root watering probe delivers water directly into the root zone of shrubs and trees. It connects to a garden hose and is easy to use.
Insert the probe on four sides of each plant and apply water until it begins to overflow. Probes are available in water-only versions or models that allow nutrient supplements. These can be found at Amazon, Home Depot, Lowe’s, or Ace. - Professional Care If you prefer not to manage winter watering yourself, many tree and landscape companies offer this service. They can also provide guidance on caring for your trees and shrubs. Costs vary significantly, so obtain multiple estimates. Confirm that the company will deliver the appropriate amount of water to each plant. A common standard is 10 gallons of water per inch of tree caliper per watering.