Blog

When to Plant Potatoes in Sept-Iles, QC

Potatoes

Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.

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 70°F, so choose short-season varieties of Potatoes to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Potatoes 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

How Much Potatoes to Grow

3-5 lbs
Average yield per plant
5
Plants per person
10 sq ft
Space per person

For a family of 4, plant approximately 20 potatoes plants in about 40 sq ft. In Sept-Iles's 140-day season, you'll have plenty of time for a full harvest. Plan your garden layout →

Potatoes Planting Timeline — Sept-Iles, QC

Potatoes Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors June 6 Jun 6 – Jun 20
Direct Sow May 30 May 30 – Jun 20
Harvest August 15 Aug 15 – Oct 24

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

70–120 days

🧪 Soil pH

Needs 5–6.5 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

140 days in Sept-Iles

Growing Tips for Sept-Iles

Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Cucumber
  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Sept-Iles is in Zone 4a with an average last frost of May 16. Plan your Potatoes planting based on this frost date — 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.

🌱

Your Sept-Iles Garden Planner — Free

A 22-page printable planner built for Sept-Iles (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.