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When to Plant Escarole in Dubuque County, IA

Escarole is a broad-leaved endive with slightly bitter, sturdy leaves. The outer leaves are more bitter while the blanched heart is tender and mild.

Dubuque County, Iowa is in USDA Zone 4b. The average last spring frost is April 29 and the first fall frost is October 9, giving you a growing season of approximately 163 days.

At an elevation of 1,243 feet, Dubuque County receives approximately 36.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Escarole to ensure they mature before fall.

Dubuque County, IA (Zone 4b) Moderate season
163 days
Last Spring Frost April 29
163 growing days
First Fall Frost October 9

Dubuque County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 13 Transplant: Apr 24 🍅 Harvest: Jun 19 – Jul 17
Recommended (50%) ✓ Fits season (79 days to spare)
Start indoors: Mar 18 Transplant: Apr 29 🍅 Harvest: Jun 24 – Jul 22
Safe Start (90%) ✓ Fits season (73 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: Jul 10 – Aug 7

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
0.4″/week
Watering frequency 1-2 times/week
Season total 621 gal / 100 sq ft
Drought risk

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

Escarole needs ~735 GDD — county provides 1,996 GDD Excellent fit

Escarole Planting Timeline โ€” Dubuque County, IA

Escarole 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 17 Jul 17 โ€“ Jul 31
Harvest June 24 Jun 24 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

50โ€“70 days

Soil pH

5.5 โ€“ 7

USDA Zone

Zone 4b

Growing Season

163 days

Growing Tips for Dubuque County

Direct sow in spring or late summer. Blanch heads by tying outer leaves together or covering with a pot for 2 weeks before harvest. Excellent braised or in soups.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Escarole in Dubuque County, IA?

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

What planting zone is Dubuque County, IA?

Dubuque County, Iowa is in USDA Hardiness Zone 4b. The average last spring frost is April 29 and first fall frost is October 9.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dubuque 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 Dubuque County, IA. Local conditions may vary. Last updated: April 2026.