Your Complete Spring Yard Prep Guide for Northern Colorado

March: The Assessment Month

Don't touch the lawn in March. Walk it, assess it, plan for it — but let it come out of dormancy on its own schedule. The worst thing you can do in early spring is power-rake or aerate soil that's still frozen two inches down, or apply fertilizer to turf that hasn't woken up yet.

March Tasks

✓ Assess winter damage — walk the entire property and note bare spots, dead areas, and areas with snow mold matting. Document with photos.

✓ Book irrigation startup — contractors fill up in April. Schedule your spring startup now.

✓ Book aeration/overseeding — if you plan to renovate in fall, get on schedules now. Good contractors book 6–8 weeks out during peak season.

✓ Check fence posts — after freeze-thaw, loose posts need to be identified and scheduled for repair before wind season (April–May on the Front Range).

✓ Order seed if overseeding in spring — have materials on hand so you're not waiting for a restock.

April: Start-Up Month

✓ Irrigation startup — once overnight lows are consistently above 32°F (usually mid-April along the Front Range). Run each zone, check each head.

✓ Pre-emergent crabgrass control — apply when soil temperatures hit 50°F consistently. Soil thermometer or local extension service temperature monitoring guides timing.

✓ Light spring fertilization — balanced slow-release once turf is actively growing (not just green, but actively growing). Wait for mowing to be needed before fertilizing.

✓ Rake snow mold — in areas with persistent gray matting, gently rake to break up the mat and allow air circulation. Most cases grow out without intervention.

May: Growth Management Month

Pro Tip: Resist the urge to fertilize heavily in May. Colorado lawns grow aggressively in May–June and don't need pushing. Heavy spring nitrogen leads to excessive thatch buildup that causes problems through summer.

✓ First mowing — begin mowing at the correct height for your grass type. Don't take off more than one-third at first mow.

✓ Spot seed bare areas — with soil temperatures above 55°F, grass seed germinates. Keep seeded areas moist.

✓ Bed prep — clean out beds, remove winter debris, refresh mulch, begin planting annuals after May 15 (last frost date along the Front Range is typically May 7–15 depending on location).

✓ Late spring fertilization — around Memorial Day, apply the main spring feed.

Updated on: 29/04/2026