Montreal Planting Schedule 2026 — Zone 5b Quebec Vegetable Guide

Montreal gardeners work in Hardiness Zone 5b — one of the colder zones among major Canadian cities, with a last frost around May 9–15. The frost-free window of roughly 148 days demands careful timing. Get your seed-starting and transplant dates right, and Montreal's warm, humid summers deliver excellent tomatoes, corn, squash, and beans.

For a personalized schedule, use the MyGardenPlanner.ca planting calculator — enter your Montreal postal code for crop-by-crop seed-starting and transplant windows.

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Montreal Frost Dates 2026

Important: The Island of Montreal creates a mild urban heat island — gardens in Plateau-Mont-Royal, Rosemont, or Outremont often see last frost 5–7 days earlier than surrounding suburbs. Laval and the South Shore (Longueuil, Brossard) are typically Zone 6a, with a last frost closer to May 1.

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How Montreal Compares to Other Canadian Cities

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Montreal Planting Schedule — Full Table

Cool-Season Crops (frost-tolerant)

Warm-Season Crops (frost-sensitive)

Fall Planting

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Tomatoes in Montreal — What Works in Zone 5b

Montreal's warm, humid July and August are good for tomatoes — but the short season means variety selection matters.

Best varieties for Zone 5b Montreal:

• Early Girl (57 days) — Reliable slicer; widely available in Quebec
• Celebrity (70 days) — Disease-resistant (VFN), dependable in Montreal's wet summers
• Sun Gold (65 days) — Cherry tomato; excellent flavour, prolific from August onward
• Juliet (60 days) — Crack-resistant grape tomato; holds on the vine
• Manitoba (60 days) — Heritage variety bred for short seasons; good for Quebec conditions
• Roma (75 days) — Paste tomato; works in warm years in Zone 5b

Varieties to use with caution: Long-season heirlooms like Brandywine (80–90 days) need a Wall-O-Water early start and a hot summer to ripen reliably in Zone 5b.

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Growing Season Notes

Heat accumulation: Montreal gets warmer summer temperatures than Vancouver or BC's coast — July averages 26°C highs — which helps heat-demanding crops that Vancouver struggles with.

Humidity: Montreal's humid continental summers bring risk of early blight and septoria leaf spot on tomatoes from mid-July onward. Choose disease-resistant varieties and maintain good air circulation.

Late springs: In Zone 5b, a late frost in the third week of May is not unusual. Keep row cover available through the Victoria Day weekend — a hard frost after that date is rare but possible.

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Month-by-Month Montreal Garden Calendar

March

• Start onions and leeks indoors (March 1–10)
• Start broccoli, cauliflower, and cabbage (March 15–25)
• Start tomatoes and peppers (March 25–April 5 for tomatoes; March 15–25 for peppers)
• Order seeds if not already done

April

• Start cucumbers, squash, and basil (late April)
• Direct sow peas and spinach outdoors once soil is workable (April 20–May 1)
• Direct sow radishes and lettuce outdoors
• Harden off brassica starts for transplant in early May

May — Critical Month

• May 1–10: Transplant brassicas, onions, leeks (frost-tolerant)
• May 20: Safe transplant date for frost-sensitive crops in Zone 5b
• May 20–June 1: Transplant tomatoes, peppers, cucumbers, squash
• Direct sow beans and corn after May 20
• Keep frost protection on hand through Victoria Day

June

• Stake tomatoes and begin removing suckers
• Monitor for aphids on broccoli and kale
• Side-dress heavy feeders (tomatoes, corn) with compost

July

• First harvests: peas, lettuce, radishes, broccoli
• Watch for early blight on tomatoes — remove affected leaves immediately
• Sow fall kale and spinach (July 1–15)

August

• Main harvest season: tomatoes, beans, cucumbers, zucchini
• Sow fall spinach and lettuce (August 1)
• Order seed garlic if not available locally

September

• Continue harvesting until frost
• Direct sow cover crops on empty beds
• Harvest and cure winter squash before first frost

October

• October 1–15: Plant garlic before ground freezes
• Mulch garlic with 4–6 inches of straw after first hard freeze
• Clear beds and add compost for next year

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Get Your Personalized Montreal Planting Dates

The dates in this guide are based on Montreal's Zone 5b average last frost of May 9–15. South Shore and Laval gardeners (Zone 6a) can transplant 1–2 weeks earlier.

Use the MyGardenPlanner.ca planting calculator for a personalized 2026 schedule with crop-by-crop seed-starting countdowns and transplant windows.

Plan your Montreal garden at MyGardenPlanner.ca →

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Frequently Asked Questions

When is the last frost date in Montreal in 2026? Montreal's average last spring frost is May 9–15. For frost-sensitive crops like tomatoes and peppers, the safe transplant date is May 20, when frost risk falls below 10%.

What hardiness zone is Montreal? Montreal is Hardiness Zone 5b (Canadian system). South shore suburbs (Longueuil, Brossard, Boucherville) and Laval often reach Zone 6a.

When should I start tomatoes indoors in Montreal? Start tomato seeds indoors March 25–April 5 — 6–8 weeks before your May 20–June 1 transplant date.

When do I plant garlic in Montreal? Plant garlic October 1–15. Montreal's fall soil cools quickly, so planting before mid-October gives cloves time to root before hard freeze. Mulch with 4–6 inches of straw.

Can I grow melons in Montreal? Yes, but marginally. Choose early varieties (Hales Best, 80 days) and give them a Wall-O-Water or black plastic mulch. Hot urban microclimate spots improve success rates significantly.

What vegetables are easiest to grow in Montreal Zone 5b? Tomatoes (short-season varieties), beans, zucchini, peas, lettuce, kale, carrots, and beets are all reliable performers in Zone 5b. Focus on varieties rated under 75 days for tomatoes and under 85 days for corn.