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When to Plant Radishes in Quebec

Published: April 24, 2026 · Updated: April 27, 2026

Fresh red radishes pulled from a garden bed
Canadian Zones 4b–5bLast frost: May 6 – May 1

The fastest crop in the garden — ready in 22–30 days. Direct sow 4–6 weeks before last frost and succession plant every 2 weeks for a continuous spring harvest.

Radishes grow well in this province with appropriate variety selection and standard Canadian planting timing.

Radishes Planting Window for Quebec

Direct sow outdoors: March 27–April 6

Minimum soil temperature: 4°C (40°F)

Days to harvest: 2230 days

Sun requirement: Full sun to partial shade

Fall crop planting: September 5–15

Direct sow radishes 4–6 weeks before last frost — one of the fastest crops in the garden. Ready in as little as 22 days. Succession plant every 2 weeks for continuous harvest.

Quebec Cities — Radishes Planting Dates

City-specific frost dates and radish planting windows for Quebec.

Growing Radishes in Quebec

  • Thin to 2-inch spacing when seedlings are an inch tall — crowded radishes produce small woody roots.
  • Succession plant every 10–14 days from early spring through late spring for continuous harvest.
  • Plant as a row marker for slow-germinating crops like carrots — radishes sprout in days and mark the rows.
  • Harvest promptly at target size; over-mature radishes turn pithy, woody, and unpleasantly hot.

Companion Planting for Radishes

In Quebec gardens, pair radish with Lettuce, Carrot, Pea, Cucumber. Avoid planting near Hyssop, Grape, which compete with or inhibit radish growth.

Common Pests and Problems

Radishes in Quebec are commonly affected by Flea Beetle, Cabbage Root Maggot, Aphid. Floating row covers installed at planting block most adult pests from laying eggs, and a weekly scouting routine catches infestations before they damage the crop.

Frequently Asked Questions

When should I plant radish in Quebec?

In Quebec (Canadian Zones 4b–5b), direct sow radish around March 27. Radishes grow well in this province with appropriate variety selection and standard Canadian planting timing.

What is the best radish variety for Quebec?

Quebec gardeners should prioritise varieties bred for shorter seasons or Canadian climates. For radishes in Canadian Zones 4b–5b, look for cultivars labelled under 30 days to maturity. Local nurseries and provincial seed exchanges curate varieties that ripen within Canadian frost-free windows.

How does Quebec's climate affect radish?

Quebec spans Canadian Zones 4b–5b with frost-free seasons ranging from roughly 138 to 162 days. Radishes actually prefer the cooler spring and fall windows typical of Quebec, making them one of the most reliable crops in the province.

Can I grow radish in containers in Quebec?

Yes. Container growing on balconies and patios extends the viable growing area across every Canadian province. Dark-coloured containers warm up faster in spring and extend the season on both ends. Choose a 5-gallon or larger pot for radish and water daily during hot summer weather, since containers dry out quickly.

When is the first fall frost in Quebec?

First fall frost dates in Quebec range from October 5 in the coldest areas to October 10 in the warmest. For a fall radish crop, count back from your local first-frost date and plant around September 5–15.

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