When to Plant Onion in Selkirk, MB
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.
Selkirk, Manitoba is in USDA Zone 4b. The average last spring frost is May 9 and the first fall frost is October 3, giving you a growing season of approximately 147 days.
At an elevation of 744 feet, Selkirk receives approximately 13.2 inches of rainfall annually with predominantly black chernozem soil. Summer highs average 70°F, so choose short-season varieties of Onion to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Onion successfully. Mulch heavily to conserve soil moisture.
Selkirk Soil Profile
Soil Type
Black Chernozem
Soil pH
6.0-7.0
Drainage
Well Drained
Onion Planting Timeline — Selkirk, MB
Onion Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 28 | Mar 28 – Apr 11 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 2 | May 2 – May 23 |
| Harvest | August 8 | Aug 8 – Sep 26 |
| Fall Sowing | July 11 | Jul 11 – Jul 25 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Fall Sowing |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 4b
📆 Growing Season
147 days in Selkirk
Growing Tips for Selkirk
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
Check more plant combinations with our Companion Planting Checker →
Onion in Other Locations
Frequently Asked Questions
When should I plant Onion in Selkirk, MB?
Selkirk is in Zone 4b with an average last frost of May 9. Plan your Onion planting based on this frost date — see the calendar above for exact timing.
What planting zone is Selkirk, MB?
Selkirk, Manitoba is in USDA Hardiness Zone 4b. The average last spring frost is May 9 and first fall frost is October 3.
Your Selkirk Garden Planner — Free
A 22-page printable planner built for Selkirk (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.