When to Plant Sunflower in Southeast Fairbanks, AK
Your May planting checklist for Southeast Fairbanks, Alaska
Welcome to May in Zone 2a. These are the moves that will have the biggest impact on your growing season.
June will be here before you know it — start on
- Transplants going out: sunflower
- Direct-sowing: sunflower
Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.
Southeast Fairbanks, Alaska is in USDA Zone 2a. The average last spring frost is June 6 and the first fall frost is August 17, giving you a growing season of approximately 72 days.
At an elevation of 1,414 feet, Southeast Fairbanks receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 62°F, so choose short-season varieties of Sunflower to ensure they mature before fall.
Southeast Fairbanks Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.6
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 Southeast Fairbanks
How your county's soil matches Sunflower's growing requirements.
Soil pH
Your soil pH (4.9–6.6) is more acidic than Sunflower prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Southeast Fairbanks is excellent for Sunflower — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Sunflower prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.
Organic Matter
Organic matter is excellent (6.3%) — Sunflower will thrive.
How to Plant Sunflower
Plant Water Budget
Monthly Watering Guide for Sunflower
Sunflower needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Sunflower Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2" | 0" | ❄️ Dormant |
| Feb | — | 1.6" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 1.4" | 0" | ❄️ Dormant |
| May | — | 1.8" | 0" | ❄️ Dormant |
| Jun | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 5.9" | 0" | ✅ Rainfall sufficient |
| Sep | — | 6.6" | 0" | ❄️ Dormant |
| Oct | — | 4.5" | 0" | ❄️ Dormant |
| Nov | — | 3.3" | 0" | ❄️ Dormant |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Jun–Aug in Southeast Fairbanks). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Sunflower 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.
Sunflower Planting Timeline — Southeast Fairbanks, AK
Sunflower Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 4 | Apr 4 – Apr 18 |
| Transplant Outdoors | June 27 | Jun 27 – Jul 11 |
| Direct Sow | June 20 | Jun 20 – Jul 11 |
| Harvest | September 5 | Sep 5 – Oct 24 |
Plant 1" deep · 18" apart · Rows 30" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | — |
| June | Transplant Outdoors Direct Sow |
| July | Transplant Outdoors Direct Sow |
| August | — |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 2a
📆 Growing Season
72 days in Southeast Fairbanks
Growing Tips for Sunflower in Southeast Fairbanks
Direct sow Sunflower outdoors after June 06 in Southeast Fairbanks when soil has warmed and frost danger has passed.
Your 72.0-day growing season in Southeast Fairbanks is tight for Sunflower (70.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Sunflower in Other Locations
Frequently Asked Questions
When should I plant Sunflower in Southeast Fairbanks, AK?
Southeast Fairbanks is in Zone 2a with an average last frost of June 6. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.
What planting zone is Southeast Fairbanks, AK?
Southeast Fairbanks, Alaska is in USDA Hardiness Zone 2a. The average last spring frost is June 6 and first fall frost is August 17.
Your Southeast Fairbanks Garden Planner — Free
A 24-page printable planner built for Southeast Fairbanks (Zone 2a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.