When to Plant Brussels Sprouts in Fairbanks North Star Borough, AK
Your May gardening checklist
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
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Plant out brussels sprouts
Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.
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Scatter brussels sprouts into prepared beds
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
Get ahead of June
- Starting indoors: brussels sprouts
- Fall sowing: brussels sprouts
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
Fairbanks North Star Borough, Alaska is in USDA Zone 3b. The average last spring frost is May 15 and the first fall frost is September 8, giving you a growing season of approximately 116 days.
At an elevation of 2,540 feet, Fairbanks North Star Borough receives approximately 29.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 69°F, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.
Fairbanks North Star Borough Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.4
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.
Soil Compatibility in Fairbanks North Star Borough
How your county's soil matches Brussels Sprouts's growing requirements.
Soil pH
Your soil pH (5.2–6.4) is more acidic than Brussels Sprouts prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Fairbanks North Star Borough is excellent for Brussels Sprouts — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Brussels Sprouts.
Organic Matter
Organic matter is excellent (6.7%) — Brussels Sprouts will thrive.
How to Plant Brussels Sprouts
Fall planting: Sow 12 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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 1" | 0" | ❄️ Dormant |
| Apr | — | 1" | 0" | ❄️ Dormant |
| May | 3.9" | 1.2" | 2.7" | 🚿 Regular watering |
| Jun | 3.9" | 2.4" | 1.5" | 💧 Light watering |
| Jul | 3.9" | 3.3" | 0.6" | 💧 Light watering |
| Aug | 3.9" | 4.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3.9" | 5.3" | 0" | ✅ Rainfall sufficient |
| Oct | — | 3.8" | 0" | ❄️ Dormant |
| Nov | — | 2.2" | 0" | ❄️ Dormant |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Fairbanks North Star Borough). 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 — Fairbanks North Star Borough, AK
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 3 | Apr 3 – Apr 17 |
| Transplant Outdoors | May 15 | May 15 – May 29 |
| Direct Sow | May 8 | May 8 – May 29 |
| Harvest | August 14 | Aug 14 – Sep 18 |
| Fall Sowing | June 16 | Jun 16 – Jun 30 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Fall Sowing |
| July | — |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Natural rainfall sufficient
📅 Days to Maturity
90–130 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 3b
📆 Growing Season
116 days in Fairbanks North Star Borough
Growing Tips for Brussels Sprouts in Fairbanks North Star Borough
Direct sow Brussels Sprouts outdoors after May 15 in Fairbanks North Star Borough when soil has warmed and frost danger has passed.
Your 116.0-day growing season in Fairbanks North Star Borough is tight for Brussels Sprouts (90.0-130.0 days to maturity). Start indoors and choose early-maturing varieties.
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
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in Fairbanks North Star Borough, AK?
Fairbanks North Star Borough is in Zone 3b with an average last frost of May 15. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is Fairbanks North Star Borough, AK?
Fairbanks North Star Borough, Alaska is in USDA Hardiness Zone 3b. The average last spring frost is May 15 and first fall frost is September 8.
Your Fairbanks North Star Borough Garden Planner — Free
A 24-page printable planner built for Fairbanks North Star Borough (Zone 3b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.