Blog

When to Plant Cucumber in Sangamon County, IL

Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

Sangamon County, Illinois is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.

At an elevation of 1,204 feet, Sangamon County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Cucumber during the growing season.

Sangamon County, IL (Zone 5b) Moderate season
185 days
Last Spring Frost April 15
185 growing days
First Fall Frost October 17

Sangamon County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 5 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Mar 11 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 19
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Mar 24 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1

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
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 1-2 times/week
Season total 1,120 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Cucumber needs ~825 GDD — county provides 2,543 GDD Excellent fit

Cucumber Planting Timeline โ€” Sangamon County, IL

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 โ€“ Mar 25
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Harvest June 24 Jun 24 โ€“ Aug 19

Plant 0.5" deep ยท 24" apart ยท Rows 48" 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

High โ€” keep soil consistently moist

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

185 days

Growing Tips for Sangamon County

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Level Up Your Garden

Frequently Asked Questions

When should I plant Cucumber in Sangamon County, IL?

Sangamon County is in Zone 5b with an average last frost of April 15. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sangamon County, IL?

Sangamon County, Illinois is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sangamon County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sangamon County, IL. Local conditions may vary. Last updated: April 2026.