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When to Plant Endive in Black Hawk County, IA

Endive is a leafy green with a slightly bitter flavor, available in curly (frisee) and broad-leaved (escarole) types. It adds texture and complexity to salads.

Black Hawk County, Iowa is in USDA Zone 4b. The average last spring frost is April 29 and the first fall frost is October 7, giving you a growing season of approximately 161 days.

At an elevation of 1,380 feet, Black Hawk County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Endive to ensure they mature before fall.

Black Hawk County, IA (Zone 4b) Moderate season
161 days
Last Spring Frost April 29
161 growing days
First Fall Frost October 7

Black Hawk County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 12 Transplant: Apr 23 🍅 Harvest: Jun 11 – Jul 16
Recommended (50%) ✓ Fits season (77 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 17 – Jul 22
Safe Start (90%) ✓ Fits season (72 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jul 1 – Aug 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
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 1 gal / 100 sq ft
Drought risk

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

Endive needs ~715 GDD — county provides 2,093 GDD Excellent fit

Endive Planting Timeline โ€” Black Hawk County, IA

Endive Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 โ€“ Apr 1
Transplant Outdoors April 29 Apr 29 โ€“ May 13
Direct Sow April 22 Apr 22 โ€“ May 13
Fall Sowing July 15 Jul 15 โ€“ Jul 29
Harvest June 17 Jun 17 โ€“ Jul 22

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

45โ€“65 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 4b

Growing Season

161 days

Growing Tips for Black Hawk County

Sow seeds directly in spring or fall. Blanch heads by tying outer leaves together 2-3 weeks before harvest to reduce bitterness. Keep soil evenly moist.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Endive in Black Hawk County, IA?

Black Hawk County is in Zone 4b with an average last frost of April 29. Plan your Endive planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Black Hawk County, IA?

Black Hawk County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 29 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Black Hawk County gardeners in Zone 4b 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 Black Hawk County, IA. Local conditions may vary. Last updated: April 2026.