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When to plant Romanesco in Jasper County, IL

Spring Romanesco in Jasper County goes in March 30–April 20, once nighttime temps stop dipping near freezing. A second sowing from August 11 to August 25 extends the harvest into fall.

When to Plant Romanesco in Jasper County, IL

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

Jasper County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 20, giving you a growing season of approximately 190 days.

At an elevation of 1,384 feet, Jasper County receives approximately 35 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Romanesco during the growing season.

Jasper County, IL (Zone 6b) Moderate season
190 days
Last Spring Frost April 13
190 growing days
First Fall Frost October 20

Jasper County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.7" 0" ✅ Rainfall sufficient
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jasper County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Romanesco Planting Timeline — Jasper County, IL

Romanesco Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 29 Jun 29 – Aug 10
Fall Sowing August 11 Aug 11 – Aug 25

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

190 days in Jasper County

Growing Tips for Jasper County

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 Jasper County, IL?

Jasper County is in Zone 6b with an average last frost of April 13. Plan your Romanesco planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jasper County, IL?

Jasper County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 20.

When should I plant Romanesco in Jasper County, IL?

In Jasper County, IL, plant Romanesco after the last frost (around April 13) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Jasper County, IL for Romanesco?

Jasper County sits in USDA Zone 6b. Romanesco grows reliably in zones 3a through 10b, so it's a good fit here.

Can Romanesco grow in Jasper County's climate?

Yes — Romanesco grows well in Jasper County's temperate climate. Jasper County averages a 190-day frost-free season, with last frost around April 13 and first frost around October 20.

🌱

Your Jasper County Garden Planner — Free

A 22-page printable planner built for Jasper County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Jasper County, IL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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