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When to Plant Butternut Squash in Juneau City and Borough, AK

Juneau City and Borough, Alaska Zone 7a May

May in the garden — Juneau City and Borough, Alaska

Each item below is timed to Juneau City and Borough, Alaska's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost May 3
Avg. first frost October 2
Soil temp (4") 65°F
Watering High
Pest pressure Moderate
Daylight 16.5 hrs
  1. Plant out butternut squash

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Sow butternut squash where they'll grow

    These tolerate cool soil, so you're not gambling by sowing now.

  3. Get butternut squash seeds going inside

    Label every cell. You will absolutely forget which is which otherwise.

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Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.

Juneau City and Borough, Alaska is in USDA Zone 7a. The average last spring frost is May 3 and the first fall frost is October 2, giving you a growing season of approximately 152 days.

At an elevation of 930 feet, Juneau City and Borough receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 57°F, so choose short-season varieties of Butternut Squash to ensure they mature before fall.

Juneau City and Borough, AK (Zone 7a) Moderate season
152 days
Last Spring Frost May 3
152 growing days
First Fall Frost October 2
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Juneau City and Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Start indoors: Mar 30 Transplant: May 11 🍅 Harvest: Aug 10 – Sep 14
Recommended (50%) ✓ Fits season (12 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Aug 16 – Sep 20
Safe Start (90%) ✓ Fits season (19 days to spare)
Start indoors: Apr 19 Transplant: May 31 🍅 Harvest: Aug 30 – Oct 4

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 Juneau City and Borough

How your county's soil matches Butternut Squash's growing requirements.

Soil pH

Your soil pH (5.1–6.5) is more acidic than Butternut Squash prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Juneau City and Borough is excellent for Butternut Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (6.7%) — Butternut Squash will thrive.

How to Plant Butternut Squash

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

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
1.0″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 150 gal / 100 sq ft

Monthly Watering Guide for Butternut Squash

Butternut Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Butternut Squash Needs Rainfall You Supplement Action
Jan 2" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 1" 0" ❄️ Dormant
May 4.8" 1.6" 3.2" 🚿 Regular watering
Jun 4.8" 3.1" 1.7" 💧 Light watering
Jul 4.8" 4.4" 0.4" 💧 Light watering
Aug 4.8" 5.3" 0" ✅ Rainfall sufficient
Sep 4.8" 6.5" 0" ✅ Rainfall sufficient
Oct 4.8" 4.1" 0.7" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Juneau City and Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Butternut Squash 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.

Butternut Squash needs ~0 GDD — county provides 0 GDD May not mature

Butternut Squash Planting Timeline — Juneau City and Borough, AK

Butternut Squash Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 10 May 10 – May 31
Harvest August 16 Aug 16 – Sep 20

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · Only during dry spells

📅 Days to Maturity

85–110 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

152 days in Juneau City and Borough

Growing Tips for Butternut Squash in Juneau City and Borough

Direct sow Butternut Squash outdoors after May 03 in Juneau City and Borough when soil has warmed and frost danger has passed.

Common pests for Butternut Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Butternut Squash in Juneau City and Borough, AK?

Juneau City and Borough is in Zone 7a with an average last frost of May 3. Plan your Butternut Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Juneau City and Borough, AK?

Juneau City and Borough, Alaska is in USDA Hardiness Zone 7a. The average last spring frost is May 3 and first fall frost is October 2.

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Your Juneau City and Borough Garden Planner — Free

A 24-page printable planner built for Juneau City and Borough (Zone 7a). 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 Juneau City and Borough, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.