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When to Plant Sunchoke in Haines Borough, AK

Haines Borough, Alaska Zone 5b May

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.

Avg. last frost May 7
Avg. first frost September 29
Soil temp (4") 58°F
Watering High
Pest pressure Low
Daylight 16.6 hrs
  1. Harden off and plant sunchoke

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

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Sunchokes (Jerusalem artichokes) are a native sunflower relative grown for their knobby, nutty-flavored tubers. They are extremely productive and nearly impossible to eradicate.

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 Sunchoke to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sunchoke root diseases.

Haines Borough, AK (Zone 5b) Short season
145 days
Last Spring Frost May 7
145 growing days
First Fall Frost September 29
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Haines Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 12 🍅 Harvest: Sep 1 – Oct 27
Recommended (50%) ✗ May not fit
Transplant: May 21 🍅 Harvest: Sep 10 – Nov 5
Safe Start (90%) ✗ May not fit
Transplant: Jun 11 🍅 Harvest: Oct 1 – Nov 26

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 Sunchoke's growing requirements.

Soil pH

Your soil pH (4.9–6.4) is more acidic than Sunchoke prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Haines Borough is excellent for Sunchoke — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Sunchoke.

Organic Matter

Organic matter is excellent (6.6%) — Sunchoke will thrive.

How to Plant Sunchoke

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.7″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sunchoke

Sunchoke needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Sunchoke 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.

Sunchoke 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.

Sunchoke needs ~130 GDD — county provides 145 GDD Good fit

Sunchoke Planting Timeline — Haines Borough, AK

Sunchoke Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest September 10 Sep 10 – Nov 5

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July
August
September Harvest
October Harvest
November Harvest
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

110–150 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

145 days in Haines Borough

Growing Tips for Sunchoke in Haines Borough

Direct sow Sunchoke 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 Sunchoke (110.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Sunchoke in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Plant tubers 4 inches deep in early spring. Contain plants with barriers as they spread aggressively. Harvest after frost or leave in ground and dig as needed through winter.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunchoke in Haines Borough, AK?

Haines Borough is in Zone 5b with an average last frost of May 7. Plan your Sunchoke 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.

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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.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Haines Borough, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

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