Author: Dianne DeLongchamps
What is dormant-season watering and does my Northern Colorado lawn need it?
Dormant-season watering is occasional watering you give your lawn in winter, after the grass has gone dormant and the sprinkler system is shut down for the season. CSU Extension recommends watering during extended dry periods without snow cover, and only when air and soil temperatures are above 40 degrees. How often depends on the weather, how much moisture the soil has, and the temperature; CSU’s guidance ranges from about once or twice a month (Fact Sheet 7.211) to every four to six weeks (Fact Sheet 7.202).
Fort Collins, Windsor, and Timnath lawns go through this every winter, and it catches a lot of people who moved here from wetter climates off guard, since it sounds backwards to water grass that isn’t growing. Winter watering is a completely different, much lighter routine, and it only applies once your automatic system is already off for the season.
What CSU Extension actually recommends
CSU Extension’s fall and winter watering fact sheet is specific about frequency and conditions. It says to monitor weather conditions and water during extended dry periods without snow cover, about once or twice each month, rather than on a fixed weekly schedule regardless of weather. It says to water only when air and soil temperatures are above 40 degrees with no snow cover, and to apply the water during midday so it has time to soak in before possible freezing at night.
Why a dormant lawn still needs any water at all
Even though the visible grass blades have stopped growing and turned tan or brown for winter, the crown and roots underneath are still alive and still depend on some soil moisture. Colorado winters can go weeks without much snow cover. CSU Extension’s guidance for trees and shrubs near the lawn describes this same dry-winter risk for shallow-rooted plants, and the same fact sheet applies that dry-winter risk to lawns.
How to water once your sprinklers are off
By the time dormant watering season rolls around, most sprinkler systems in Fort Collins, Windsor, and Timnath have already been professionally blown out for winter. A hose-end sprinkler, run for a short cycle on a mild, above-freezing day, is the standard way to apply this water by hand. PlantTalk Colorado’s winter watering guidance describes a similar approach for trees and shrubs near the lawn, with a small sprinkler run in place for about 30 minutes at each setting.
How this is different from summer watering
Dormant watering isn’t a scaled-down version of Clean Air Lawn Care’s growing-season standard. During the season, that standard is one to two inches of water a week, two inches during the mid-July to mid-August stretch, applied across two to three deep waterings. Winter watering is a different rhythm entirely: occasional, done by hand, and tied to dry stretches rather than a weekly schedule, because the lawn isn’t actively growing and doesn’t need anywhere near that much water.
Who needs it most
- South- or west-facing slopes and windy sites, which dry out faster during dry winter stretches than sheltered or shaded ground
- Any lawn during a long, dry, open winter without much snow cover
- Newly seeded or sodded lawns. CSU Extension’s fall and winter watering fact sheet specifically names these as needing extra attention, the same way it does for newly planted trees and shrubs
The fact sheet’s wording is that susceptibility increases for lawns with south or west exposures, that windy sites result in faster drying of sod and plants and require additional water, and that newly established lawns, whether seeded or sodded, are especially susceptible.
What about the trees and shrubs near your lawn?
The same fact sheet gives trees and shrubs their own numbers. As a general survival rule, it says to apply 10 gallons of water for each diameter inch of a tree, and it gives monthly gallon amounts for shrubs by size. It says to decrease those amounts to account for precipitation, and it says most evergreen plants also benefit from winter watering. Those amounts are for trees and shrubs, not for turf, so a day when you water the lawn is not automatically a day your trees got what they need. Our post on protecting trees and shrubs near your lawn before winter covers that routine.
Keeping track of the watering window
The easiest way to stay on top of this without overthinking it is the same habit that helps with sprinkler timing in fall: keep half an eye on the forecast. If it’s been snow-free and dry for a few weeks and there’s an above-40-degree, calm day coming up, that’s a reasonable window to get a light watering down, rather than trying to track it against a fixed date on a calendar. PlantTalk Colorado, writing about trees, says to water early in the day, and CSU Extension says midday. The goal in both cases is time for the water to soak in before nighttime freezing.
If you’re not sure whether your lawn needs it this winter, just ask us.
Clean Air Lawn Care Northern Colorado is owned by Dianne, Paul, and Luke DeLongchamps — a family business serving Fort Collins, Windsor, and Timnath with organic lawn treatments and solar-powered electric equipment.
