When to Plant Green Beans in London, ON
Published: April 24, 2026 · Updated: April 27, 2026
One of the easiest and most productive direct-sow vegetables. Bush beans need no support and produce in 50–60 days; pole beans need a trellis but produce for months.
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.
Green Beans Planting Calendar for London
Direct sow outdoors: May 10–20
Harvest window: June 29 – July 14
Minimum soil temperature: 16°C (60°F)
Days to harvest: 50–65 days
Sun requirement: Full sun
Fall crop planting: August 25–September 4 (harvest October 14)
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 Green Beans
- Direct sow only — beans do not transplant successfully.
- Succession plant every 2–3 weeks for continuous harvest throughout the season.
- Do not over-fertilize with nitrogen — beans fix their own nitrogen from the soil.
- Harvest every 2 days at finger-length; leaving beans on the vine signals the plant to stop producing.
Companion Planting in London
Pair green bean with Carrot, Cucumber, Summer Savory, Marigold for mutual benefit. Avoid planting near Onion, Garlic, Fennel, which compete with or inhibit green bean growth.
Pests and Problems to Watch in London
The most common pest and disease pressure on green beans in London comes from Mexican Bean Beetle, Aphids, Spider Mite, Bean Mosaic Virus. 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 green bean in London?
London's last spring frost is around May 3. Direct sow May 10–20.
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 green bean crop (50–65 days to maturity) before the first fall frost.
Can I grow green bean 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. For a fall green bean crop, plant around August 25–September 4 so plants mature before the first killing frost.