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When to Plant Onion in North Okanagan, BC

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

North Okanagan, British Columbia is in USDA Zone 6b. The average last spring frost is April 19 and the first fall frost is October 23, giving you a growing season of approximately 187 days.

At an elevation of 1,282 feet, North Okanagan receives approximately 39.5 inches of rainfall annually with predominantly podzolic loam soil. Summer highs average 82°F, so choose short-season varieties of Onion to ensure they mature before fall.

North Okanagan, BC (Zone 6b) Moderate season
187 days
Last Spring Frost April 19
187 growing days
First Fall Frost October 23
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North Okanagan Soil Profile

Soil Type

Podzolic Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (43 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2
Recommended (50%) ✓ Fits season (43 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2
Safe Start (90%) ✓ Fits season (43 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jul 15 – Sep 2

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 188 gal / 100 sq ft

Monthly Watering Guide for Onion

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

Month Onion Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.9" 0" ✅ Rainfall sufficient
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 3.9" 0.4" 💧 Light watering
Aug 4.3" 4" 0.3" 💧 Light watering
Sep 4.3" 3.9" 0.4" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.8" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in North Okanagan). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Onion needs ~1,208 GDD — county provides 2,150 GDD Excellent fit

Onion Planting Timeline — North Okanagan, BC

Onion Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 5 Apr 5 – Apr 26
Harvest July 19 Jul 19 – Sep 6
Fall Sowing August 14 Aug 14 – Aug 28

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

187 days in North Okanagan

Growing Tips for Onion in North Okanagan

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in North Okanagan, BC?

North Okanagan is in Zone 6b with an average last frost of April 19. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is North Okanagan, BC?

North Okanagan, British Columbia is in USDA Hardiness Zone 6b. The average last spring frost is April 19 and first fall frost is October 23.

🌱

Your North Okanagan Garden Planner — Free

A 24-page printable planner built for North Okanagan (Zone 6b). 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 North Okanagan, BC. Local conditions may vary. Last updated: May 2026.

Sources & credits

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