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When to Plant Squash (Summer) in Lewis County, WA

Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.

Lewis County, Washington is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 24, giving you a growing season of approximately 182 days.

At an elevation of 327 feet, Lewis County receives approximately 37.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Squash (Summer) during the growing season.

Lewis County, WA (Zone 7b) Moderate season
182 days
Last Spring Frost April 25
182 growing days
First Fall Frost October 24

Lewis County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jun 15 – Aug 17
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Mar 28 Transplant: May 9 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (24 days to spare)
Start indoors: May 27 Transplant: Jul 8 🍅 Harvest: Aug 26 – Oct 28

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 Lewis County

How your county's soil matches Squash (Summer)'s growing requirements.

Soil pH

Your soil pH (5.6โ€“6.2) is more acidic than Squash (Summer) prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Lewis County is excellent for Squash (Summer) โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.3%) โ€” Squash (Summer) will thrive.

How to Plant Squash (Summer)

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

Succession Planting Squash (Summer)

4
successive plantings in your 182-day season

Sow every 5.1 weeks. Last sowing by Aug 20 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 226 gal / 100 sq ft

Monthly Watering Guide for Squash (Summer)

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

Month Squash (Summer) Needs Rainfall You Supplement Action
Jan โ€” 5.6" 0" โ„๏ธ Dormant
Feb โ€” 3.6" 0" โ„๏ธ Dormant
Mar โ€” 4.1" 0" โ„๏ธ Dormant
Apr 4.3" 2.8" 1.5" ๐Ÿ’ง Light watering
May 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Jun 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Jul 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Aug 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Sep 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 6.3" 0" โ„๏ธ Dormant
Dec โ€” 5.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Lewis County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Squash (Summer) 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" โ€” every day above 50ยฐF 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.

Squash (Summer) needs ~798 GDD — county provides 2,639 GDD Excellent fit

Squash (Summer) Planting Timeline โ€” Lewis County, WA

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 28 Mar 28 โ€“ Apr 11
Transplant Outdoors May 9 May 9 โ€“ May 23
Direct Sow May 2 May 2 โ€“ May 23
Harvest June 27 Jun 27 โ€“ Aug 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“65 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

182 days in Lewis County

Growing Tips for Squash (Summer) in Lewis County

Direct sow Squash (Summer) outdoors after April 25 in Lewis County when soil has warmed and frost danger has passed.

Your generous 182.0-day season in Lewis County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.

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

General growing tips

Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Summer) in Lewis County, WA?

Lewis County is in Zone 7b with an average last frost of April 25. Plan your Squash (Summer) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lewis County, WA?

Lewis County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lewis County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Lewis County, WA. Local conditions may vary. Last updated: April 2026.