When to Plant Eggplant in London, 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.
London's Canadian Zone 6a (USDA 5b) southwestern Ontario climate delivers adequate rainfall, warm summers, and 170 frost-free days. Shorter than Toronto's season but long enough for reliable production of most warm-season crops with appropriate variety selection.
Eggplant Planting Calendar for London
Start seeds indoors: March 1–8
Transplant outdoors: May 24–June 3
Harvest window: July 28 – August 12
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.
London Climate Notes
London has 150-170 frost-free days — adequate for most warm-season crops when transplants go in by late May. The region's rich soils support heavy feeders like tomatoes and brassicas with minimal amendment.
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 London
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 London
The most common pest and disease pressure on eggplant in London 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 London?
London's last spring frost is around May 3. Start seeds indoors March 1–8. Transplant outdoors May 24–June 3.
What Canadian hardiness zone is London?
London is in Canadian Zone 6a (USDA equivalent 5b). The southwestern Ontario temperate climate delivers 170 frost-free days from May 3 to October 20, which shapes every planting date in the local calendar.
How long is London's growing season?
London has 170 frost-free days — from May 3 in spring to October 20 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 London?
Yes. Container growing on balconies and decks is practical in London — 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 London?
London's average first fall frost is October 20. Most eggplant in London is a single spring-timed planting designed to harvest before the first fall frost.