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When to Plant Radish in Sept-Iles, QC

Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.

Sept-Iles, Quebec is in USDA Zone 4a. The average last spring frost is May 16 and the first fall frost is October 3, giving you a growing season of approximately 140 days.

At an elevation of 173 feet, Sept-Iles receives approximately 19.5 inches of rainfall annually with predominantly gray-brown podzol soil. Summer highs average 70ยฐF, so choose short-season varieties of Radish to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Radish successfully. Mulch heavily to conserve soil moisture.

Sept-Iles, QC (Zone 4a) Short season
140 days
Last Spring Frost May 16
140 growing days
First Fall Frost October 3

Sept-Iles Soil Profile

Soil Type

Gray-Brown Podzol

Soil pH

6.0-7.0

Drainage

Well Drained

Monthly Watering Guide for Radish

Radish needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Radish Needs Rainfall You Supplement Action
Jan โ€” 0.8" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 1.3" 0" โ„๏ธ Dormant
Apr โ€” 1.9" 0" โ„๏ธ Dormant
May 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Jun 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Jul 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Aug 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Sep 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Oct 4.3" 1.5" 2.8" ๐Ÿšฟ Regular watering
Nov โ€” 1.5" 0" โ„๏ธ Dormant
Dec โ€” 1" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Sept-Iles). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Radish Planting Timeline โ€” Sept-Iles, QC

Radish Planting Calendar

Activity When Date Range
Direct Sow May 9 May 9 โ€“ May 30
Harvest June 6 Jun 6 โ€“ Jun 27
Fall Sowing July 11 Jul 11 โ€“ Jul 25

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Harvest
July Fall Sowing
August โ€”
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

22โ€“35 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

140 days in Sept-Iles

Growing Tips for Sept-Iles

Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.

Companion Planting

Good Companions

Avoid Planting Near

  • Hyssop

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radish in Sept-Iles, QC?

Sept-Iles is in Zone 4a with an average last frost of May 16. Plan your Radish planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sept-Iles, QC?

Sept-Iles, Quebec is in USDA Hardiness Zone 4a. The average last spring frost is May 16 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sept-Iles gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sept-Iles, QC. Local conditions may vary. Last updated: April 2026.