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When to Plant Romanesco in Dearborn County, IN

Romanesco is a stunning brassica with a lime-green head composed of fractal-patterned spiraling florets. It has a nuttier, milder flavor than cauliflower.

Dearborn County, Indiana is in USDA Zone 6a. The average last spring frost is April 16 and the first fall frost is October 20, giving you a growing season of approximately 187 days.

At an elevation of 1,290 feet, Dearborn County receives approximately 32.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Romanesco during the growing season.

Dearborn County, IN (Zone 6a) Moderate season
187 days
Last Spring Frost April 16
187 growing days
First Fall Frost October 20

Dearborn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: Jun 25 – Aug 6
Recommended (50%) ✓ Fits season (68 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: Jul 2 – Aug 13
Safe Start (90%) ✓ Fits season (65 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jul 17 – Aug 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.

Soil Compatibility in Dearborn County

How your county's soil matches Romanesco's growing requirements.

Soil pH

Your soil pH (5.9โ€“7.3) overlaps with Romanesco's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Dearborn County is excellent for Romanesco โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Romanesco.

How to Plant Romanesco

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Romanesco

2
successive plantings in your 187-day season

Sow every 8.6 weeks. Last sowing by Jul 12 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 453 gal / 100 sq ft

Monthly Watering Guide for Romanesco

Romanesco needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Romanesco Needs Rainfall You Supplement Action
Jan โ€” 1.3" 0" โ„๏ธ Dormant
Feb โ€” 1.5" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
May 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Jun 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Jul 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Aug 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Sep 4.3" 2.7" 1.6" ๐Ÿ’ง Light watering
Oct 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Dearborn County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Romanesco Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" โ€” every day above 50ยฐF deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Romanesco needs ~1,203 GDD — county provides 2,571 GDD Excellent fit

Romanesco Planting Timeline โ€” Dearborn County, IN

Romanesco Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 2 Apr 2 โ€“ Apr 23
Harvest July 2 Jul 2 โ€“ Aug 13
Fall Sowing August 11 Aug 11 โ€“ Aug 25

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

75โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

187 days in Dearborn County

Growing Tips for Romanesco in Dearborn County

Direct sow Romanesco outdoors after April 16 in Dearborn County when soil has warmed and frost danger has passed.

Common pests for Romanesco in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 5-7 weeks before transplanting. Provide consistent moisture and avoid temperature stress. Harvest when head is fully formed but before florets begin to separate.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Romanesco in Dearborn County, IN?

Dearborn County is in Zone 6a with an average last frost of April 16. Plan your Romanesco planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Dearborn County, IN?

Dearborn County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 16 and first fall frost is October 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Dearborn County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Dearborn County, IN. Local conditions may vary. Last updated: April 2026.