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When to Plant Broccoli Rabe in Blackford County, IN

Broccoli rabe (rapini) is a brassica grown for its slightly bitter, nutty-flavored florets, leaves, and stems. It is a staple in Italian cooking.

Blackford County, Indiana is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 16, giving you a growing season of approximately 173 days.

At an elevation of 729 feet, Blackford County receives approximately 32.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87ยฐF, providing good warmth for Broccoli Rabe during the growing season.

Blackford County, IN (Zone 5b) Moderate season
173 days
Last Spring Frost April 26
173 growing days
First Fall Frost October 16

Blackford County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 3 – Jul 8
Recommended (50%) ✓ Fits season (96 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 7 – Jul 12
Safe Start (90%) ✓ Fits season (90 days to spare)
Start indoors: Apr 7 Transplant: May 12 🍅 Harvest: Jun 23 – Jul 28

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
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 317 gal / 100 sq ft
Broccoli Rabe needs ~762 GDD — county provides 2,638 GDD Excellent fit

Broccoli Rabe Planting Timeline โ€” Blackford County, IN

Broccoli Rabe Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 โ€“ Apr 5
Transplant Outdoors April 26 Apr 26 โ€“ May 10
Direct Sow April 12 Apr 12 โ€“ May 3
Fall Sowing August 7 Aug 7 โ€“ Aug 21
Harvest June 7 Jun 7 โ€“ Jul 12

Plant 1" deep ยท 15" apart ยท Rows 24" 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 Harvest
August Fall Sowing
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

40โ€“60 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 5b

Growing Season

173 days

Growing Tips for Blackford County

Direct sow in spring or fall. Harvest when small yellow flower buds first appear but before they open. Cut the main shoot first to encourage side shoots.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Level Up Your Garden

Frequently Asked Questions

When should I plant Broccoli Rabe in Blackford County, IN?

Blackford County is in Zone 5b with an average last frost of April 26. Plan your Broccoli Rabe planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Blackford County, IN?

Blackford County, Indiana is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 16.

๐ŸŒฑ

Plan Your Garden with Confidence

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