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When to Plant Cucumber in Lee County, IA

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.

Lee County, Iowa is in USDA Zone 5b. The average last spring frost is April 16 and the first fall frost is October 18, giving you a growing season of approximately 185 days.

At an elevation of 1,393 feet, Lee County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Cucumber to ensure they mature before fall.

Lee County, IA (Zone 5b) Moderate season
185 days
Last Spring Frost April 16
185 growing days
First Fall Frost October 18

Lee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (59 days to spare)
Start indoors: Mar 6 Transplant: Apr 24 🍅 Harvest: Jun 19 – Aug 14
Recommended (50%) ✓ Fits season (59 days to spare)
Start indoors: Mar 12 Transplant: Apr 30 🍅 Harvest: Jun 25 – Aug 20
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Mar 28 Transplant: May 16 🍅 Harvest: Jul 11 – Sep 5

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
0.8″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,835 gal / 100 sq ft
Cucumber needs ~780 GDD — county provides 2,405 GDD Excellent fit

Cucumber Planting Timeline โ€” Lee County, IA

Cucumber Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 30 Apr 30 โ€“ May 14
Direct Sow April 23 Apr 23 โ€“ May 14
Harvest June 25 Jun 25 โ€“ Aug 20

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 Lee 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 Lee County, IA?

Lee County is in Zone 5b with an average last frost of April 16. Plan your Cucumber planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lee County, IA?

Lee County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 16 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lee County gardeners in Zone 5b 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 Lee County, IA. Local conditions may vary. Last updated: April 2026.