Ottawa Planting Calendar 2026
Ottawa (zone 5a) has 148 frost-free days with a later last frost (May 6) than Toronto. The Ottawa Valley's continental climate brings hot summers and cold winters. Start seeds indoors early to maximize the growing season.
Zone 5a • Last frost: May 6 • First fall frost: Oct 1 • 148 frost-free days
Month-by-Month Planting Schedule
When to plant 15 popular vegetables in Ottawa (zone 5a), based on the average last frost date of May 6.
April
| Vegetable | Start Indoors | Plant Outdoors | Harvest By | Frost Tolerance |
|---|---|---|---|---|
| Lettuce | Apr 1 | Apr 15 | May 30 | Semi-Hardy |
| Peas | Direct sow | Apr 1 | May 31 | Hardy |
| Carrots | Direct sow | Apr 19 | Jun 28 | Semi-Hardy |
| Kale | Apr 1 | Apr 15 | Jun 9 | Hardy |
| Broccoli | Mar 25 | Apr 22 | Jun 26 | Semi-Hardy |
| Spinach | Direct sow | Apr 1 | May 11 | Hardy |
| Radishes | Direct sow | Apr 1 | Apr 26 | Hardy |
| Onions | Feb 18 | Apr 15 | Jul 24 | Hardy |
| Potatoes | Direct sow | Apr 15 | Jul 14 | Semi-Hardy |
| Beets | Apr 5 | Apr 19 | Jun 13 | Semi-Hardy |
May
| Vegetable | Start Indoors | Plant Outdoors | Harvest By | Frost Tolerance |
|---|---|---|---|---|
| Tomatoes | Mar 18 | May 17 | Jul 31 | Very Tender |
| Peppers | Mar 4 | May 20 | Jul 29 | Very Tender |
| Beans | Direct sow | May 17 | Jul 11 | Tender |
| Cucumbers | Apr 12 | May 17 | Jul 11 | Very Tender |
| Zucchini | Apr 12 | May 17 | Jul 6 | Tender |
Complete Planting Dates for Ottawa
All 15 vegetables with indoor start, outdoor planting, and estimated harvest dates for Ottawa.
| Vegetable | Start Indoors | Plant Outdoors | Harvest By | Frost Tolerance |
|---|---|---|---|---|
| Tomatoes | Mar 18 | May 17 | Jul 31 | Very Tender |
| Peppers | Mar 4 | May 20 | Jul 29 | Very Tender |
| Lettuce | Apr 1 | Apr 15 | May 30 | Semi-Hardy |
| Peas | Direct sow | Apr 1 | May 31 | Hardy |
| Beans | Direct sow | May 17 | Jul 11 | Tender |
| Carrots | Direct sow | Apr 19 | Jun 28 | Semi-Hardy |
| Cucumbers | Apr 12 | May 17 | Jul 11 | Very Tender |
| Zucchini | Apr 12 | May 17 | Jul 6 | Tender |
| Kale | Apr 1 | Apr 15 | Jun 9 | Hardy |
| Broccoli | Mar 25 | Apr 22 | Jun 26 | Semi-Hardy |
| Spinach | Direct sow | Apr 1 | May 11 | Hardy |
| Radishes | Direct sow | Apr 1 | Apr 26 | Hardy |
| Onions | Feb 18 | Apr 15 | Jul 24 | Hardy |
| Potatoes | Direct sow | Apr 15 | Jul 14 | Semi-Hardy |
| Beets | Apr 5 | Apr 19 | Jun 13 | Semi-Hardy |
Ottawa Gardening Tips by Month
- ✓March: Start peppers, onions, and leeks indoors (8-10 weeks before last frost).
- ✓April: Start tomatoes and brassicas indoors. Direct-sow peas and spinach outdoors late April.
- ✓May: Transplant brassicas early May. Warm crops go out after last frost (around May 6).
- ✓June: Plant beans, cucumbers, squash, and corn. Succession-sow lettuce.
- ✓July: Peak growing. Harvest garlic and peas. Sow fall crops.
- ✓August: Main harvest season. Sow fall spinach, lettuce, and radishes.
- ✓September: Continue harvesting. Plant garlic by end of month.
- ✓October: First frost around Oct 1. Pull remaining warm crops; extend with row cover.
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Frequently Asked Questions
When should I start planting in Ottawa?
In Ottawa (zone 5a), the average last frost date is May 6. 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 Ottawa?
The average last spring frost in Ottawa is May 6, and the first fall frost is Oct 1, giving you approximately 148 frost-free growing days.
What vegetables grow best in Ottawa?
Hardy crops like peas, kale, spinach, and potatoes grow well across Ottawa. In zone 5a, 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 Ottawa?
Start peppers and onions 9-11 weeks before your last frost date, tomatoes 7 weeks before, and brassicas 5-6 weeks before. In Ottawa with a last frost around May 6, that means starting peppers in February and tomatoes in March.
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