Blog

When to Plant Acorn Squash in Asotin County, WA

Asotin County, Washington Zone 7a May

May in Asotin County, Washington — your action list

May is a pivotal month for Asotin County, Washington gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 9
Avg. first frost September 30
Soil temp (4") 59°F
Watering Critical
Pest pressure Low
Daylight 14.8 hrs
  1. Plant out acorn squash

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Scatter acorn squash into prepared beds

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Get ahead of June
  • Starting indoors: acorn squash

Instant PDF download. No spam, unsubscribe any time.

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.

Asotin County, Washington is in USDA Zone 7a. The average last spring frost is May 9 and the first fall frost is September 30, giving you a growing season of approximately 144 days.

At an elevation of 2,029 feet, Asotin County receives approximately 14 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°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.

Asotin County, WA (Zone 7a) Short season
144 days
Last Spring Frost May 9
144 growing days
First Fall Frost September 30

Asotin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (13 days to spare)
Start indoors: Mar 31 Transplant: May 12 🍅 Harvest: Aug 4 – Sep 8
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Apr 11 Transplant: May 23 🍅 Harvest: Aug 15 – Sep 19
Safe Start (90%) ✓ Fits season (4 days to spare)
Start indoors: May 9 Transplant: Jun 20 🍅 Harvest: Sep 12 – Oct 17

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 Asotin County

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

Soil pH

Your soil pH (5.5–6.5) is within Acorn Squash's preferred range (5.5–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — 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 144-day season

Sow every 9.1 weeks. Last sowing by Jun 22 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.4″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 886 gal / 100 sq ft

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" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 0.9" 0" ❄️ Dormant
May 4.8" 0.8" 4" 🚿 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 1.2" 0" ❄️ Dormant
Nov 2.4" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Asotin 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 ~1,238 GDD — county provides 1,980 GDD Excellent fit

Acorn Squash Planting Timeline — Asotin County, WA

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest August 15 Aug 15 – Sep 19

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 Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 1-2 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: ideal

🗺️ USDA Zone

Zone 7a

📆 Growing Season

144 days in Asotin County

Growing Tips for Acorn Squash in Asotin County

Direct sow Acorn Squash outdoors after May 09 in Asotin 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.

Asotin 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 Asotin County, WA?

Asotin County is in Zone 7a with an average last frost of May 9. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is Asotin County, WA?

Asotin County, Washington is in USDA Hardiness Zone 7a. The average last spring frost is May 9 and first fall frost is September 30.

🌱

Your Asotin County Garden Planner — Free

A 24-page printable planner built for Asotin 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Asotin 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.