Author: Dianne DeLongchamps
How do I protect trees and shrubs near my lawn before winter in Northern Colorado?
Water trees and shrubs before the ground freezes, starting when the leaves begin to fall. Give extra attention to recent transplants, evergreens, and shallow-rooted trees such as lindens, birches, and Norway or silver maples. PlantTalk Colorado says to water again whenever four weeks pass without snow cover, as long as the ground isn’t frozen and the air is above freezing.
This is homeowner guidance, not a Clean Air Lawn Care service. Our work is lawn turf, not tree and shrub care. The guidance applies to yards in Fort Collins, Windsor, and Timnath, and whether you handle it yourself or call an arborist for anything beyond basic watering, it helps to know why this matters.
Why trees near the lawn are at risk in a Colorado winter
PlantTalk Colorado’s fall and winter watering guidance points to the plants most at risk: recent transplants, evergreens, and shallow-rooted species like lindens, birches, and Norway or silver maples. These either haven’t had time to grow deep roots, or they naturally keep shallow ones, which makes them more vulnerable to Colorado’s dry winter stretches than a mature, deep-rooted tree. CSU Extension’s fall and winter watering fact sheet agrees that newly planted trees are the most susceptible to winter drought injury, and it says most evergreen plants also benefit from winter watering.
How much and where to water
Water the ground from the edge of the branches halfway in toward the trunk, and out beyond the branches by two to three times that same distance. If you’re using a soil needle, PlantTalk’s guidance calls for making injections in a grid pattern about a foot apart and 9 to 18 inches deep, on low water pressure for one minute at each site for recent transplants. If you’re using a small sprinkler instead, which PlantTalk calls a frog-eye sprinkler, run it for about 30 minutes at each setting near the tree.
The CSU Extension fact sheet adds numbers you can plan around:
- Trees: As a general survival rule, apply 10 gallons of water for each diameter inch of the tree.
- Newly planted shrubs: Apply 5 gallons two times per month.
- Small established shrubs (less than 3 feet tall): Apply 5 gallons monthly.
- Large established shrubs (more than 6 feet tall): Apply 18 gallons monthly.
The fact sheet also says to decrease those amounts to account for precipitation.
Timing: watch the thermometer, not the calendar
PlantTalk says to start watering when the leaves start to fall in the autumn, to send trees and shrubs into winter with adequate soil moisture. From November through March, water only when temperatures are above freezing and the soil isn’t frozen, and do it early in the day so the water can soak in before nighttime freezing returns. If four weeks pass without snow cover, water again.
CSU Extension’s fact sheet sets a slightly stricter bar: water during extended dry periods without snow cover, about once or twice each month, and only when air and soil temperatures are above 40 degrees. It suggests applying the water during midday so it has time to soak in before possible freezing at night.
How this connects to your sprinkler shutdown
Once your sprinkler system has been professionally blown out for the season, which usually happens ahead of the first hard freeze, you won’t have automatic water for trees any more than you will for your lawn. A hose-end sprinkler or a soil needle, run by hand on a mild day, is the standard way to keep both trees and dormant turf watered through winter.
Why this is separate from lawn watering
Keep tree and shrub watering separate from lawn watering, even if both happen with a hose on the same mild winter day. CSU Extension’s own fall and winter watering fact sheet treats lawn turf and landscape trees as separate topics with separate watering rules, so watering the lawn on a given day doesn’t automatically mean nearby trees got what they needed, and the reverse is true too. Lawn timing for the same stretch of winter is in our post on dormant-season watering for Fort Collins lawns.
Your winter routine at a glance
Here is the whole plan in order, using the PlantTalk Colorado and CSU Extension guidance above:
Anything beyond watering: Call an arborist.
When the leaves start to fall: Water trees and shrubs so they go into winter with adequate soil moisture.
November through March: Check the weather. If four weeks have passed without snow cover, and the soil isn’t frozen, water again.
Each time you water: Pick a mild day, apply the water early in the day or at midday, and reduce the amounts when snow or rain has added moisture.
Newly planted trees: Put these first on your list, because CSU Extension says newly planted trees are the most susceptible to winter drought injury.
If a tree near your lawn needs more than watering, an arborist is worth the call.
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.
