Month-by-month planting calendar for Montreal homeowners

Montreal's growing season runs roughly 157 to 165 frost-free days, starting in late April or early May and ending in early to mid October. Getting your planting timing right means the difference between thriving plants and wasted effort.

This calendar draws on Environment Canada Climate Normals for Montreal and frost date data from the Old Farmer's Almanac (using Environment Canada historical data). Montreal's average last spring frost falls around late April to early May, and the first fall frost typically arrives in early October.

January and February: plan and prepare

These are Montreal's coldest months. Average daily highs sit around -4 to -3 C, with overnight lows dropping to -13 to -11 C, according to Environment Canada Climate Normals via Current Results. The ground stays frozen solid under snow cover that persists roughly 104 days through winter.

Use this time to order seeds, sketch out your garden layout, and review what worked last year. If you're planning a landscaping project, this is also the right time to get estimates. We provide free quotes by phone, photo, or video at 514-900-3867.

March: start seeds indoors

Average highs reach about 3 C, but overnight lows still hover around -6 C. Snow covers the ground for most of March, with about 34 cm of fresh snowfall typical for the month.

Start cool-season vegetables indoors: tomatoes, peppers, and eggplant should go into seed trays about 6 to 8 weeks before your planned transplant date. For a late May transplant, that means starting in late March.

April: early outdoor work begins

Temperatures climb to average highs of 11 C. The snow melts, and you can start raking debris, assessing winter damage, and cleaning up garden beds. Soil temperature stays cool, so hold off on planting most things directly outdoors.

You can plant cold-hardy vegetables like peas, spinach, lettuce, and radishes in late April if the ground has thawed enough to work. Bare-root trees and shrubs can also go in the ground during this window.

This is also a strong month to start hardscaping projects. Paver patios, walkways, and retaining walls can get underway as soon as frost leaves the ground.

May: the main planting push

May marks the real start of Montreal's growing season. Average highs reach 20 C, and lows rise to about 9 C. The average last frost date falls around late April to early May, but keep an eye on the forecast through mid-May before putting out tender plants.

After the risk of frost has passed:

• Transplant tomatoes, peppers, squash, and cucumbers outdoors
• Plant annual flowers like marigolds, petunias, and impatiens
• Lay sod or seed new lawns (Montreal's watering regulations allow daily watering for 15 days after sodding or seeding)
• Plant perennials, shrubs, and trees

May is also the ideal time to fertilize your lawn for the first time. Soil temperatures need to be consistently above 10 C for fertilizer to work properly.

June: peak planting and establishment

Average highs hit 24 C, making June one of the best months for plant establishment. Everything you planted in May should be growing well now.

• Continue planting annuals and perennials
• Succession-plant beans, lettuce, and herbs every two weeks
• Begin regular lawn mowing (keep cool-season grass at 7 to 8 cm)
• Prune spring-flowering shrubs like lilacs right after they finish blooming

Late June is also the recommended window for the first cedar hedge trim of the season. According to Space for Life (Montreal Botanical Garden), pruning in late June targets the period after most new growth has finished.

July: maintain and harvest

Montreal's warmest month brings average highs of 27 C. The focus shifts from planting to maintenance.

• Water deeply and less frequently rather than doing shallow daily watering
• Harvest early vegetables (lettuce, radishes, peas, beans)
• Deadhead annual flowers to encourage more blooms
• Watch for pest and disease issues in the heat

You can still plant container-grown trees and shrubs, but they'll need consistent watering to establish in the heat.

August: second-wave planting

Average highs remain warm at 26 C. Late August opens the fall planting window for cool-season lawns.

• Start fall vegetable crops: plant lettuce, spinach, kale, and radishes for autumn harvest
• Begin overseeding thin lawn areas in late August through mid September
• Plan and plant fall-blooming perennials
• Divide and transplant perennials like hostas and daylilies while conditions are favorable

September: fall planting season

Average highs of 22 C and cooler nights (lows around 12 C) create ideal conditions for root establishment. September is actually one of the best months for planting trees, shrubs, and perennials in Montreal.

• Plant trees and shrubs so roots can establish before the ground freezes
• Overseed and patch lawns (soil stays warm, rain tends to be more reliable)
• Plant spring-flowering bulbs like tulips, daffodils, and crocuses
• Apply fall lawn fertilizer in early to mid September

October: wrap up and protect

The first fall frost arrives in early October. Average highs drop to 14 C, and lows reach about 5 C.

• Finish planting spring bulbs before the ground freezes
• Apply a final winterizer fertilizer application in early October
• Clean up fallen leaves from the lawn
• Cut back perennials after they've gone dormant
• Protect tender plants with mulch

November: winterize

Average highs of 6 C and lows of -2 C signal the end of the outdoor season. Snow often arrives this month.

• Drain and store garden hoses
• Wrap young or vulnerable trees to protect from frost cracking
• Apply a final layer of mulch around perennial beds
• Shut down irrigation systems

December: rest

The ground is frozen. The garden rests under snow. Start planning for next year.

Get your yard ready

Whether you're planning a new lawn, a paver patio, or a full landscape renovation, timing your project around Montreal's growing season makes all the difference. Call us at 514-900-3867 or send photos of your yard for a free estimate.