When to Plant Brussels Sprouts in Calgary, AB
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
Calgary, Alberta is in USDA Zone 5a. The average last spring frost is May 7 and the first fall frost is October 14, giving you a growing season of approximately 160 days.
At an elevation of 3,428 feet, Calgary receives approximately 26.9 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 75°F, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.
Calgary Soil Profile
Soil Type
Dark Brown Chernozem
Soil pH
6.0-7.0
Drainage
Well Drained
Plant Planting Risk Windows
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 Brussels Sprouts
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Monthly Watering Guide for Brussels Sprouts
Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Brussels Sprouts Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.1" | 0" | ❄️ Dormant |
| Feb | — | 1.2" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 2.5" | 0" | ❄️ Dormant |
| May | 3.9" | 3.3" | 0.6" | 💧 Light watering |
| Jun | 3.9" | 3.3" | 0.6" | 💧 Light watering |
| Jul | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| Aug | 3.9" | 2.9" | 1" | 💧 Light watering |
| Sep | 3.9" | 2.1" | 1.8" | 💧 Light watering |
| Oct | 3.9" | 2" | 1.9" | 💧 Light watering |
| Nov | — | 1.9" | 0" | ❄️ Dormant |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Calgary). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Brussels Sprouts 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.
Brussels Sprouts Planting Timeline — Calgary, AB
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 2 | Apr 2 – Apr 16 |
| Transplant Outdoors | May 7 | May 7 – May 21 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Harvest | August 6 | Aug 6 – Oct 1 |
| Fall Sowing | August 5 | Aug 5 – Aug 19 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | — |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Only during dry spells
📅 Days to Maturity
90–130 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 5a
📆 Growing Season
160 days in Calgary
Growing Tips for Brussels Sprouts in Calgary
Common pests for Brussels Sprouts in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in Calgary, AB?
Calgary is in Zone 5a with an average last frost of May 7. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is Calgary, AB?
Calgary, Alberta is in USDA Hardiness Zone 5a. The average last spring frost is May 7 and first fall frost is October 14.
Your Calgary Garden Planner — Free
A 24-page printable planner built for Calgary (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.