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When to Plant Acorn Squash in Chelan County, WA

Chelan County, Washington Zone 7a May

This month in Chelan County, Washington

Your Chelan County, Washington garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 24
Avg. first frost October 20
Soil temp (4") 54°F
Watering Critical
Pest pressure Low
Daylight 14.9 hrs
  1. Move acorn squash into the garden

    Your last frost (April 24) has passed. These warm-season crops can handle outdoor soil now.

  2. Seed acorn squash outdoors

    Keep the top inch of soil moist until germination — a gentle morning watering for 5–7 days does the job.

  3. Begin indoor sowing: acorn squash

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

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Acorn squash is a small winter squash with dark green, ribbed skin and mildly sweet orange flesh. It is perfect for stuffing and roasting as individual servings.

Chelan County, Washington is in USDA Zone 7a. The average last spring frost is April 24 and the first fall frost is October 20, giving you a growing season of approximately 179 days.

At an elevation of 3,517 feet, Chelan County receives approximately 14.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Acorn Squash during the growing season. With low rainfall, drip irrigation is essential for growing Acorn Squash successfully. Mulch heavily to conserve soil moisture.

Chelan County, WA (Zone 7a) Moderate season
179 days
Last Spring Frost April 24
179 growing days
First Fall Frost October 20
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Chelan County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (47 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jul 20 – Aug 24
Recommended (50%) ✓ Fits season (46 days to spare)
Start indoors: Mar 27 Transplant: May 8 🍅 Harvest: Jul 31 – Sep 4
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Apr 21 Transplant: Jun 2 🍅 Harvest: Aug 25 – Sep 29

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 Chelan County

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

Soil pH

Your soil pH (5.5–6.3) is within Acorn Squash's preferred range (5.5–7.0).

Soil Texture

The silt loam soil in Chelan County is excellent for Acorn Squash — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) — Acorn Squash will thrive.

How to Plant Acorn Squash

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

Succession Planting Acorn Squash

2
successive plantings in your 179-day season

Sow every 9.1 weeks. Last sowing by Jul 12 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.3″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,466 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Acorn Squash

Acorn 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 Acorn Squash Needs Rainfall You Supplement Action
Jan 2.1" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 1.2" 0" ❄️ Dormant
Apr 4.8" 1.2" 3.6" 🚿 Regular watering
May 4.8" 0.9" 3.9" 🚿 Regular watering
Jun 4.8" 0.6" 4.2" 🚿 Regular watering
Jul 4.8" 0.2" 4.6" 🚿 Regular watering
Aug 4.8" 0.3" 4.5" 🚿 Regular watering
Sep 4.8" 0.5" 4.3" 🚿 Regular watering
Oct 4.8" 1.2" 3.6" 🚿 Regular watering
Nov 1.9" 0" ❄️ Dormant
Dec 2.5" 0" ❄️ Dormant

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

Acorn 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.

Acorn Squash needs ~1,372 GDD — county provides 2,729 GDD Excellent fit

Acorn Squash Planting Timeline — Chelan County, WA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 8 May 8 – May 22
Direct Sow May 1 May 1 – May 22
Harvest July 31 Jul 31 – Sep 4

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

179 days in Chelan County

Growing Tips for Acorn Squash in Chelan County

Direct sow Acorn Squash outdoors after April 24 in Chelan County when soil has warmed and frost danger has passed.

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

Chelan County receives only 14" of rain annually. Acorn Squash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when the ground spot turns orange and the skin is hard. Acorn squash has a shorter storage life than butternut, lasting about 2 months.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Acorn Squash in Chelan County, WA?

Chelan County is in Zone 7a with an average last frost of April 24. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Chelan County, WA?

Chelan County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is April 24 and first fall frost is October 20.

🌱

Your Chelan County Garden Planner — Free

A 24-page printable planner built for Chelan County (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 Chelan County, WA. 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.