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When to plant Brussels Sprouts in Hamilton County, IA

Brussels Sprouts planted in Hamilton County between April 17 and May 8 matures in 90–130 days — well before the October 7 first frost. A second sowing from July 29 to August 12 extends the harvest into fall.

When to Plant Brussels Sprouts in Hamilton County, IA

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.

Hamilton County, Iowa is in USDA Zone 5a. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 1,210 feet, Hamilton County receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Brussels Sprouts to ensure they mature before fall.

Hamilton County, IA (Zone 5a) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Hamilton County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Brussels Sprouts Planting Timeline — Hamilton County, IA

Brussels Sprouts Planting Calendar

Activity When Date Range
Start Indoors March 27 Mar 27 – Apr 10
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 17 Apr 17 – May 8
Harvest July 31 Jul 31 – Sep 25
Fall Sowing July 29 Jul 29 – Aug 12

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June
July Fall Sowing 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 5a

📆 Growing Season

159 days in Hamilton County

Growing Tips for Hamilton 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 Hamilton County, IA?

Hamilton County is in Zone 5a with an average last frost of May 1. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, IA?

Hamilton County, Iowa is in USDA Hardiness Zone 5a. The average last spring frost is May 1 and first fall frost is October 7.

When should I plant Brussels Sprouts in Hamilton County, IA?

In Hamilton County, IA, plant Brussels Sprouts after the last frost (around May 1) and before the first frost (around October 7). Best results when soil holds above 50°F.

What growing zone is Hamilton County, IA for Brussels Sprouts?

Hamilton County sits in USDA Zone 5a. Brussels Sprouts grows reliably in zones 2a through 10b, so it's a good fit here.

Can Brussels Sprouts grow in Hamilton County's climate?

Yes — Brussels Sprouts grows well in Hamilton County's temperate climate. Hamilton County averages a 159-day frost-free season, with last frost around May 1 and first frost around October 7.

🌱

Your Hamilton County Garden Planner — Free

A 22-page printable planner built for Hamilton County (Zone 5a). 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 Hamilton County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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