When to Plant Eggplant in Ottawa, ON
Published: April 24, 2026 · Updated: April 27, 2026
Warm-season nightshade requiring the longest indoor start of any common vegetable — 8–10 weeks before last frost. Needs soil above 15°C and consistent summer heat; intolerant of cold below 10°C.
Ottawa's Canadian Zone 5b (USDA 5a) continental climate brings cold winters, hot summers, and higher frost risk than Toronto thanks to the inland location. The 153 frost-free days from early May through early October is adequate for most vegetables, but variety selection — short-season cultivars under 70 days — matters significantly.
Eggplant Planting Calendar for Ottawa
Start seeds indoors: March 4–11
Transplant outdoors: May 27–June 6
Harvest window: July 31 – August 15
Minimum soil temperature: 16°C (60°F)
Days to harvest: 65–80 days
Sun requirement: Full sun (8+ hours)
⚠ Start eggplant indoors 8–10 weeks before last frost — same timing as peppers. Transplant 2–3 weeks after last frost when soil is above 60°F. Needs heat and full sun. Does not tolerate cold — protect from temps below 50°F.
Ottawa Climate Notes
Ottawa Valley winters are harsh. Choose short-season tomato varieties under 70 days (Stupice, Sunrise, Sub-Arctic Plenty) and transplant only after the May long weekend. Fall garden extends the productive season into October with cold-tolerant greens and brassicas.
Growing Tips for Eggplant
- Use a heat mat during germination — eggplant seeds need 24–27°C soil to sprout reliably.
- Protect transplants from cold spring nights — temperatures below 10°C halt growth for weeks.
- Use stakes or small cages — eggplant stems bend or break under the weight of mature fruit.
- Harvest while fruit skin is glossy; dull skin signals an over-ripe, bitter, seedy interior.
Companion Planting in Ottawa
Pair eggplant with Pepper, Bean, Basil, Marigold for mutual benefit. Avoid planting near Fennel, Brassicas, which compete with or inhibit eggplant growth.
Pests and Problems to Watch in Ottawa
The most common pest and disease pressure on eggplant in Ottawa comes from Flea Beetle, Colorado Potato Beetle, Spider Mite, Verticillium Wilt. Floating row covers through the first 4–6 weeks after planting block adult pests from laying eggs, and a weekly scouting routine catches infestations before they damage the crop.
Other Ontario Cities
Frequently Asked Questions
When do I plant eggplant in Ottawa?
Ottawa's last spring frost is around May 6. Start seeds indoors March 4–11. Transplant outdoors May 27–June 6.
What Canadian hardiness zone is Ottawa?
Ottawa is in Canadian Zone 5b (USDA equivalent 5a). The continental inland climate delivers 153 frost-free days from May 6 to October 6, which shapes every planting date in the local calendar.
How long is Ottawa's growing season?
Ottawa has 153 frost-free days — from May 6 in spring to October 6 in fall. That is more than enough time to finish a full eggplant crop (65–80 days to maturity) before the first fall frost.
Can I grow eggplant in containers in Ottawa?
Yes. Container growing on balconies and decks is practical in Ottawa — choose a 5-gallon or larger dark-coloured container to warm the root zone, use a high-quality potting mix, and water daily during hot summer weather. In milder climates, containers extend both spring and fall windows by several weeks.
What is the first fall frost in Ottawa?
Ottawa's average first fall frost is October 6. Most eggplant in Ottawa is a single spring-timed planting designed to harvest before the first fall frost.