When to Plant Blackberries in Haines Borough, AK
Your May gardening checklist
We've pulled the most time-sensitive tasks for Haines Borough, Alaska this May and put them front and centre. Tackle them in order.
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Set out blackberries seedlings
Frost risk is low now in Haines Borough, Alaska. If you've been covering beds overnight, you can stop.
Blackberries are vigorous bramble fruits that produce sweet-tart berries on thorny or thornless canes. They are prolific producers and relatively low-maintenance once established.
Haines Borough, Alaska is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is September 29, giving you a growing season of approximately 145 days.
At an elevation of 1,921 feet, Haines Borough receives approximately 57.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 68°F, so choose short-season varieties of Blackberries to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Blackberries root diseases.
Haines Borough Soil Profile
Soil Type
Silt Loam
Soil pH
4.9-6.4
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 Haines Borough
How your county's soil matches Blackberries's growing requirements.
Soil pH
Your soil pH (4.9–6.4) overlaps with Blackberries's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Haines Borough is excellent for Blackberries — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Blackberries.
Organic Matter
Organic matter is excellent (6.6%) — Blackberries will thrive.
How to Plant Blackberries
Plant Water Budget
Monthly Watering Guide for Blackberries
Blackberries needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Blackberries Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2.8" | 0" | ❄️ Dormant |
| Feb | — | 2.6" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 2" | 0" | ❄️ Dormant |
| May | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Jun | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jul | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.5" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 10.6" | 0" | ✅ Rainfall sufficient |
| Oct | — | 6.5" | 0" | ❄️ Dormant |
| Nov | — | 4.1" | 0" | ❄️ Dormant |
| Dec | — | 3.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Haines Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Blackberries 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.
Blackberries Planting Timeline — Haines Borough, AK
Blackberries Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | May 28 | May 28 – Jun 11 |
· 24" apart · Rows 72" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Transplant Outdoors |
| June | Transplant Outdoors |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
365–730 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
145 days in Haines Borough
Growing Tips for Blackberries in Haines Borough
Direct sow Blackberries outdoors after May 07 in Haines Borough when soil has warmed and frost danger has passed.
Your 145.0-day growing season in Haines Borough is tight for Blackberries (365.0-730.0 days to maturity). Start indoors and choose early-maturing varieties.
General growing tips
Plant bare-root canes in spring. Provide a sturdy trellis system. Prune out spent fruiting canes after harvest. New canes fruit in their second year (floricanes).
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Blackberries in Other Locations
Frequently Asked Questions
When should I plant Blackberries in Haines Borough, AK?
Haines Borough is in Zone 5b with an average last frost of May 7. Plan your Blackberries planting based on this frost date — see the calendar above for exact timing.
What planting zone is Haines Borough, AK?
Haines Borough, Alaska is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is September 29.
Your Haines Borough Garden Planner — Free
A 24-page printable planner built for Haines Borough (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.