When to Plant Turnips in London, ON
Published: April 24, 2026 · Updated: April 27, 2026
Fast-growing cool-season root crop — some varieties ready in just 35 days. Best planted in late summer for fall harvest; frost sweetens the roots. Direct sow only; resents transplanting.
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.
Turnips Planting Calendar for London
Direct sow outdoors: April 12–22
Harvest window: May 17 – June 11
Minimum soil temperature: 4°C (40°F)
Days to harvest: 35–60 days
Sun requirement: Full sun to partial shade
Fall crop planting: August 25–September 4 (harvest September 29)
⚠ Direct sow turnips 2–4 weeks before last frost for spring crop. Best planted in late summer (6–8 weeks before first fall frost) for fall harvest — frost sweetens the roots. Fast-growing: some varieties ready in just 35 days.
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 Turnips
- Thin seedlings to 4-inch spacing when plants are 3 inches tall — crowded turnips produce small woody roots.
- Both roots AND greens are edible — harvest baby turnip greens 4 weeks after sowing, roots 5–9 weeks.
- Fall turnips are sweetest — plant 8 weeks before first frost and let cold weather convert starches to sugars.
- Succession plant every 2–3 weeks for continuous harvest through spring; skip summer heat and resume in fall.
Companion Planting in London
Pair turnip with Pea, Mint, Rosemary, Thyme for mutual benefit. Avoid planting near Potato, Radish, which compete with or inhibit turnip growth.
Pests and Problems to Watch in London
The most common pest and disease pressure on turnips in London comes from Flea Beetle, Aphid, Cabbage Root Maggot. 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 turnip in London?
London's last spring frost is around May 3. Direct sow April 12–22.
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 turnip crop (35–60 days to maturity) before the first fall frost.
Can I grow turnip 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 turnip crop, plant around August 25–September 4 so plants mature before the first killing frost.