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When to plant Brussels Sprouts in Sangamon County, IL

In Sangamon County, plant Brussels Sprouts in spring between April 1 and April 22, once soil temps hold above 50°F. Sangamon County's last frost averages April 15, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between August 8 and August 22 — roughly 90–130 days before the first frost on October 17.

When to Plant Brussels Sprouts in Sangamon County, IL

Brussels Sprouts

Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.

Sangamon County, Illinois is in USDA Zone 6a. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.

At an elevation of 1,204 feet, Sangamon County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Brussels Sprouts during the growing season.

Sangamon County, IL (Zone 6a) Moderate season
185 days
Last Spring Frost April 15
185 growing days
First Fall Frost October 17

Sangamon County Soil Profile

Soil Type

Silt Loam

Soil pH

6.2-7.2

Drainage

Well Drained

Monthly Watering Guide for Brussels Sprouts

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

Month Brussels Sprouts Needs Rainfall You Supplement Action
Jan 1.9" 0" ❄️ Dormant
Feb 1.9" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 3.3" 1" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

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

Brussels Sprouts Planting Timeline — Sangamon County, IL

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors April 15 Apr 15 – Apr 29
Direct Sow April 1 Apr 1 – Apr 22
Harvest July 15 Jul 15 – Sep 9
Fall Sowing August 8 Aug 8 – Aug 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

90–130 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

185 days in Sangamon County

Growing Tips for Sangamon County

Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.

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 Brussels Sprouts in Sangamon County, IL?

Sangamon County is in Zone 6a with an average last frost of April 15. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sangamon County, IL?

Sangamon County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 15 and first fall frost is October 17.

When should I plant Brussels Sprouts in Sangamon County, IL?

In Sangamon County, IL, plant Brussels Sprouts after the last frost (around April 15) and before the first frost (around October 17). Best results when soil holds above 50°F.

What growing zone is Sangamon County, IL for Brussels Sprouts?

Sangamon County sits in USDA Zone 6a. Brussels Sprouts grows reliably in zones 2a through 10b, so it's a good fit here.

Can Brussels Sprouts grow in Sangamon County's climate?

Yes — Brussels Sprouts grows well in Sangamon County's temperate climate. Sangamon County averages a 185-day frost-free season, with last frost around April 15 and first frost around October 17.

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Your Sangamon County Garden Planner — Free

A 22-page printable planner built for Sangamon County (Zone 6a). 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 Sangamon County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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