Edmonton Planting Calendar 2026 — Zone 3b Vegetable Guide

Edmonton gardeners work with one of Canada's most demanding growing seasons: a last frost around May 20–25, a first frost as early as September 15, and roughly 120 frost-free days in between. Every week counts. This guide gives you exact planting dates for Edmonton's Zone 3b conditions so you can make the most of every warm day.

Edmonton's Growing Zone

Edmonton falls in USDA/Canadian Hardiness Zone 3b, with some newer subdivisions in the southeast reaching Zone 4a. The city sits at roughly 700m elevation on the North Saskatchewan River valley, which creates microclimates — gardens in sheltered river valley lots often gain 1–2 extra weeks compared to exposed suburban plots.

Key dates for planning:

• Average last spring frost: May 20–25
• Average first fall frost: September 15–20
• Frost-free growing days: approximately 120–130

Indoor Seed Starting Schedule

Starting seeds indoors is not optional for Edmonton gardeners — it's essential. The short season means tomatoes, peppers, and squash simply cannot mature from direct seed.

February

• Onions and leeks — Start 10–12 weeks before last frost (mid-February). These slow germinators need a head start.
• Peppers — Start 10–12 weeks before last frost. Peppers are slow to germinate and need soil temperatures above 25°C.

March

• Tomatoes — Start 6–8 weeks before transplant date (first week of March for a late-May transplant).
• Broccoli, cabbage, cauliflower — Start 4–6 weeks before transplant.
• Celery — Start 10–12 weeks before transplant.

April

• Cucumbers, zucchini, squash — Start 3–4 weeks before last frost (late April). These grow quickly and get root-bound if started too early.
• Basil — Start 4–6 weeks before last frost.

Use the MyGardenPlanner.ca seed starting calculator to get exact indoor start dates based on your Edmonton last frost date.

Direct Sowing Outdoors

As Soon as Soil Is Workable (late April to early May)

These crops tolerate light frost and can go in before last frost:

• Peas — Sow as early as April 20 if soil is workable. Peas thrive in cool soil.
• Spinach, arugula, lettuce — Can handle light frost; sow from late April.
• Radishes — Fast-maturing; start sowing late April.
• Kale — Hardy to -4°C; direct sow or transplant from late April.

After Last Frost (May 25 onward)

Wait until all frost risk has passed:

• Beans — Soil temperature must be at least 15°C; sow May 25–June 1.
• Corn — Direct sow after May 25; needs soil at 18°C+ to germinate well.
• Cucumbers — Transplant seedlings after last frost.
• Squash and pumpkins — Transplant or direct sow after May 25.

Transplanting Schedule

Frost Protection Strategies

With frost possible through mid-May, Edmonton gardeners should keep row cover or frost blankets on hand. A single frost event can wipe out tender transplants.

• Row covers (floating row cover / Reemay) protect to about -4°C
• Cold frames extend your season by 3–4 weeks at each end — essential for Edmonton
• Wall-o-Waters allow tomatoes to be transplanted 3–4 weeks early
• Cloches protect individual plants with repurposed jugs

Fall Planting for a Second Harvest

Edmonton's fall window is short but usable. Work backward from your first frost date (September 15):

• Peas — Direct sow July 1–10 for a fall harvest
• Lettuce, spinach, arugula — Sow July 15–31 for fall crops
• Radishes — Sow August 1–15
• Kale — Harvest improves after frost; transplant July 15 for fall

Crops That Struggle in Zone 3b

Some crops are simply marginal for Edmonton and require extra effort:

• Melons — Possible with black plastic mulch and a warm microclimate, but risky
• Eggplant — Needs a warm spot and may not fully produce before frost
• Sweet potatoes — Very challenging; need 100+ warm days

Plan Your Edmonton Garden with MyGardenPlanner.ca

Getting your planting dates right is the difference between a productive Edmonton garden and a frustrating one. MyGardenPlanner.ca calculates exact seeding and transplanting dates based on your specific location — enter your city and let the planner build your personalized Edmonton planting calendar.

Check the planting dates for Alberta for a province-wide view, or use the calculator to plan individual crops around your last frost date.