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When to Plant Squash (Summer) in Saline County, IL

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

Saline County, Illinois is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 24, giving you a growing season of approximately 199 days.

At an elevation of 748 feet, Saline County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Squash (Summer) during the growing season.

Saline County, IL (Zone 6b) Moderate season
199 days
Last Spring Frost April 8
199 growing days
First Fall Frost October 24

Saline County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Start indoors: Feb 28 Transplant: Apr 18 🍅 Harvest: Jun 6 – Aug 8
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 4 Transplant: Apr 22 🍅 Harvest: Jun 10 – Aug 12
Safe Start (90%) ✓ Fits season (80 days to spare)
Start indoors: Mar 17 Transplant: May 5 🍅 Harvest: Jun 23 – Aug 25

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.

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 235 gal / 100 sq ft
Squash (Summer) needs ~880 GDD — county provides 3,184 GDD Excellent fit

Squash (Summer) Planting Timeline โ€” Saline County, IL

Squash (Summer) Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 โ€“ Mar 18
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Direct Sow April 15 Apr 15 โ€“ May 6
Harvest June 10 Jun 10 โ€“ Aug 12

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“65 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 6b

Growing Season

199 days

Growing Tips for Saline County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Squash (Summer) in Saline County, IL?

Saline County is in Zone 6b with an average last frost of April 8. Plan your Squash (Summer) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Saline County, IL?

Saline County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 24.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Saline County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

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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 Saline County, IL. Local conditions may vary. Last updated: April 2026.