Spring Lawn Care Checklist for Ontario Homeowners (2026 Guide)

Ontario's spring lawn care window is short and timing matters. Start too early and you'll compact frozen soil. Start too late and weeds get a head start. This checklist gives you the exact sequence — in the right order — to get your GTA lawn thick, green, and healthy for the season ahead.

Late March to Early April: Assessment Phase

Resist the urge to do too much too early. While the snow is melting, focus on assessment and planning.

1. Walk Your Property (Late March)

• Look for winter damage: salt damage near sidewalks and driveways, plow damage to grass edges, snow mold patches (grey or pink circles)
• Check for heaved pavers or frost-damaged edging in landscape beds
• Note bare or thin spots that will need overseeding
• Remove any debris, branches, and garbage that accumulated over winter
• Do NOT walk on your lawn when it's saturated and squishy — you'll compact the soil and leave footprints that persist all season

2. Clean Up Winter Debris (Early April)

Once the ground firms up enough to walk on without sinking, do a thorough spring cleanup:

• Rake up remaining leaves and debris missed during fall cleanup
• Remove sand and gravel deposited by snow plows along grass edges
• Clean out garden beds — remove dead perennial foliage and last year's mulch if heavily matted
• Clear any leftover salt residue with a thorough watering near walkways

Mid-April: First Actions

3. Apply Pre-Emergent Weed Control (Mid-April)

This is the most time-sensitive task of spring. Corn gluten meal (the only effective pre-emergent legal in Ontario) must be applied BEFORE soil temperatures reach 13°C — when crabgrass starts germinating. In the GTA, this is typically mid to late April.

4. Light Raking / Dethatching (Mid-April)

Once the lawn is dry enough that you're not leaving footprints, give it a light raking with a spring-tine (flexible) rake. This lifts matted grass, removes light thatch, and helps air and sunlight reach the soil. Don't power-dethatch unless thatch is over 1/2 inch thick — aggressive dethatching in spring can damage recovering grass.

Late April to May: Growth Phase

5. First Mow of the Season (Late April)

Once grass reaches 3.5 to 4 inches, it's time for the first mow. Set your mower to 3 inches for the first cut. Make sure your blades are freshly sharpened — dull blades tear grass and create brown, ragged tips that invite disease.

• Sharpen or replace mower blades before the first cut
• First cut at 3 inches (slightly lower than summer height to remove dead tips)
• Raise to 3 to 3.5 inches for all subsequent mowing
• Never remove more than 1/3 of the grass blade in a single mow
• Leave clippings on the lawn (grasscycling) — they return nitrogen to the soil

6. Spring Fertilization (Early to Mid-May)

Wait until your lawn has been actively growing for 2-3 weeks before the first fertilizer application. Fertilizing too early pushes top growth before roots are established, creating a weak lawn. Use a balanced or slightly lower-nitrogen fertilizer for spring — save the heavy nitrogen for late spring and fall.

7. Overseed Thin Spots (May)

May is the last chance to overseed before summer heat stress. Fall is actually the better time for overseeding, but spring overseeding works for small repairs. Remember: if you applied corn gluten pre-emergent, don't overseed those areas until fall.

8. Address Broadleaf Weeds (Late May)

Once dandelions and other broadleaf weeds appear, treat them with Ontario-legal iron-based herbicides like Scotts EcoSense Weed-B-Gon. Apply when temperatures are above 15°C and rain isn't expected for 24 hours. Spot-treat individual weeds rather than blanket-spraying the entire lawn.

Spring Lawn Care Mistakes to Avoid

• Walking on frozen or saturated lawn — compacts soil and damages grass crowns
• Power raking / dethatching too aggressively — damages recovering grass
• Fertilizing too early — pushes weak top growth before roots establish
• Mowing too short — scalping invites weeds and stresses grass
• Overwatering — Ontario spring rainfall is usually sufficient. Don't irrigate unless there's a dry spell
• Applying pre-emergent and overseeding the same area — corn gluten prevents all germination

Spring Lawn Care Timeline Summary

• Late March: Walk property, assess winter damage
• Early April: Spring cleanup — debris, leaves, salt residue
• Mid-April: Apply corn gluten pre-emergent (if not overseeding), light raking
• Late April: First mow at 3 inches with sharp blades
• Early May: Spring fertilization (2-3 weeks after growth starts)
• Mid-May: Overseed thin spots, begin regular mowing schedule
• Late May: Spot-treat broadleaf weeds with iron-based herbicide