Calgary Planting Calendar 2026

Calgary (zone 4a) has just 115 frost-free days with a last frost date of May 23. Late spring frosts and early fall frosts require aggressive season extension. Wall-O-Water, cold frames, and short-season varieties are essential tools for Calgary gardeners.

Zone 4a • Last frost: May 23 • First fall frost: Sep 15 115 frost-free days

Month-by-Month Planting Schedule

When to plant 15 popular vegetables in Calgary (zone 4a), based on the average last frost date of May 23.

April

VegetableStart IndoorsPlant OutdoorsHarvest ByFrost Tolerance
PeasDirect sowApr 18Jun 17Hardy
SpinachDirect sowApr 18May 28Hardy
RadishesDirect sowApr 18May 13Hardy

May

VegetableStart IndoorsPlant OutdoorsHarvest ByFrost Tolerance
LettuceApr 18May 2Jun 16Semi-Hardy
CarrotsDirect sowMay 6Jul 15Semi-Hardy
KaleApr 18May 2Jun 26Hardy
BroccoliApr 11May 9Jul 13Semi-Hardy
OnionsMar 7May 2Aug 10Hardy
PotatoesDirect sowMay 2Jul 31Semi-Hardy
BeetsApr 22May 6Jun 30Semi-Hardy

June

VegetableStart IndoorsPlant OutdoorsHarvest ByFrost Tolerance
TomatoesApr 4Jun 3Aug 17Very Tender
PeppersMar 21Jun 6Aug 15Very Tender
BeansDirect sowJun 3Jul 28Tender
CucumbersApr 29Jun 3Jul 28Very Tender
ZucchiniApr 29Jun 3Jul 23Tender

Complete Planting Dates for Calgary

All 15 vegetables with indoor start, outdoor planting, and estimated harvest dates for Calgary.

VegetableStart IndoorsPlant OutdoorsHarvest ByFrost Tolerance
TomatoesApr 4Jun 3Aug 17Very Tender
PeppersMar 21Jun 6Aug 15Very Tender
LettuceApr 18May 2Jun 16Semi-Hardy
PeasDirect sowApr 18Jun 17Hardy
BeansDirect sowJun 3Jul 28Tender
CarrotsDirect sowMay 6Jul 15Semi-Hardy
CucumbersApr 29Jun 3Jul 28Very Tender
ZucchiniApr 29Jun 3Jul 23Tender
KaleApr 18May 2Jun 26Hardy
BroccoliApr 11May 9Jul 13Semi-Hardy
SpinachDirect sowApr 18May 28Hardy
RadishesDirect sowApr 18May 13Hardy
OnionsMar 7May 2Aug 10Hardy
PotatoesDirect sowMay 2Jul 31Semi-Hardy
BeetsApr 22May 6Jun 30Semi-Hardy

Calgary Gardening Tips by Month

  • March: Start peppers and onions indoors (10 weeks before last frost).
  • April: Start tomatoes, broccoli, and herbs indoors. Set up Wall-O-Water for early tomato transplants.
  • May: Direct-sow peas, spinach, and radishes early month. Harden off transplants.
  • June: Transplant warm crops after the long weekend (late May). Direct-sow beans and corn after June 1.
  • July: Succession-sow lettuce and radishes. Monitor for hail — consider netting.
  • August: Harvest early crops. Cover tender plants on cool nights.
  • September: Frost arrives around Sep 15 — harvest remaining crops or protect with cover.

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Frequently Asked Questions

When should I start planting in Calgary?

In Calgary (zone 4a), the average last frost date is May 23. Hardy crops like peas, spinach, and radishes can be planted 3-5 weeks before this date. Tender crops like tomatoes and peppers should wait until after the last frost.

What is the last frost date in Calgary?

The average last spring frost in Calgary is May 23, and the first fall frost is Sep 15, giving you approximately 115 frost-free growing days.

What vegetables grow best in Calgary?

Hardy crops like peas, kale, spinach, and potatoes grow well across Calgary. In zone 4a, tomatoes, peppers, beans, and cucumbers also do well with proper timing. Use our free calculator for exact planting dates.

When should I start seeds indoors in Calgary?

Start peppers and onions 9-11 weeks before your last frost date, tomatoes 7 weeks before, and brassicas 5-6 weeks before. In Calgary with a last frost around May 23, that means starting peppers in March and tomatoes in April.

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