In Northern Colorado, spring (April–May) is for cleanup, aeration and the first feeding; summer (June–August) is for consistent mowing at 2.5–3 inches and smart watering; fall (September–October) is the best time for aeration, overseeding and fertilizing; and late fall through winter is for sprinkler blowouts, leaf cleanup and snow removal.
Why timing matters on the Front Range
Loveland, Fort Collins and the towns around them sit in a semi-arid climate with heavy clay soils, big temperature swings and snow that can show up from October through May. Doing the right job at the wrong time wastes money: fertilizer on dry soil doesn’t get used, and seed sown in July heat struggles to survive. This calendar lines up the work with how cool-season lawns like Kentucky bluegrass actually grow here.
March–April: wake-up and cleanup
- Spring cleanup: rake out debris, matted grass and leaves left from winter so sunlight and air reach the crown of the plant. See our cleanup service.
- Hold off on heavy feeding: CSU Extension suggests waiting until spring’s rapid green-up slows (often early May) before the main spring fertilizer.
- Plan aeration once the ground thaws and isn’t soggy.
- Book early: local crews’ spring schedules fill quickly.
May–June: core aeration, feeding and the first steady mows
- Core aeration relieves compacted clay so water soaks in instead of running off. Learn about aeration.
- Spring fertilizer and weed control while broadleaf weeds like dandelions are actively growing. See fertilization.
- Mow weekly at 2.5–3 inches and never remove more than one-third of the blade at once.
July–August: protect the lawn through heat
- Keep mowing at a consistent 2.5–3 inches. Scalping a stressed lawn invites weeds and brown spots.
- Water deeply and less often, early in the morning, and follow your city’s current watering rules.
- Spot-treat weeds rather than blanket-spraying in heat.
- Watch for dry spots near sidewalks and slopes, which often point to sprinkler coverage problems.
September–October: the most important season
- Fall aeration and overseeding fill thin areas while soil is warm and nights are cool.
- Fall fertilization builds roots and carbohydrate reserves for a faster spring green-up.
- Leaf cleanup keeps wet leaves from smothering turf under snow.
- Sprinkler blowout before sustained hard freezes. Read our blowout guide.
November–February: snow season
- Snow removal: Loveland and Fort Collins both require sidewalks to be cleared within 24 hours after a storm. Know the rules or let our snow removal crew handle it.
- Water the lawn during long dry, warm winter spells if the ground isn’t frozen.
- Lock in next season’s mowing spot.
Frequently asked questions
When should I start mowing in Northern Colorado?
Most lawns need their first mow in mid-to-late April, once grass is actively growing. Start at 2.5–3 inches and keep that height consistent.
Is spring or fall better for aeration in Colorado?
Both work. Fall is often best for aeration paired with overseeding; spring aeration helps compacted lawns before summer stress.
When is the most important time to fertilize?
Fall feeding is especially valuable for Colorado bluegrass lawns because it strengthens roots for winter and spring.