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When to plant Sunflower in Hancock County, IL

For Sunflower in Hancock County, the safe spring window opens around April 21 and closes around May 12. Last expected frost is April 14, first fall frost October 18, giving a 187-day growing season.

When to Plant Sunflower in Hancock County, IL

Sunflower (Helianthus annuus) is a fast-growing North American native annual famous for its towering stems and brilliant yellow heads. It thrives in full sun and heat, producing large, pollen-rich blooms that attract bees, butterflies, and seed-eating birds. Varieties range from 18-inch dwarfs to 12-foot giants and nearly every color except blue.

Hancock County, Illinois is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 18, giving you a growing season of approximately 187 days.

At an elevation of 758 feet, Hancock County receives approximately 37.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Sunflower during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Hancock County, IL (Zone 6a) Moderate season
187 days
Last Spring Frost April 14
187 growing days
First Fall Frost October 18

Hancock County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Sunflower Planting Timeline — Hancock County, IL

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors April 21 Apr 21 – May 5
Direct Sow April 21 Apr 21 – May 12
Bloom July 14 Jul 14 – Oct 6

Plant 1" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

70–100 days

🧪 Soil pH

Needs 6–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

187 days in Hancock County

Growing Tips for Hancock County

Direct-sow 1 inch deep after last frost; germination takes 7-14 days at 65-75°F soil. Sunflowers dislike root disturbance so direct sowing is strongly preferred over transplanting. Plant in succession every 2 weeks for extended bloom. Stake tall varieties. Avoid overwatering — they tolerate drought once established. Birds will self-deadhead seed heads; leave them up through fall for wildlife.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Pole_beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Hancock County, IL?

Hancock County is in Zone 6a with an average last frost of April 14. Plan your Sunflower planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hancock County, IL?

Hancock County, Illinois is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 18.

When should I plant Sunflower in Hancock County, IL?

In Hancock County, IL, plant Sunflower after the last frost (around April 14) and before the first frost (around October 18). Best results when soil holds above 50°F.

What growing zone is Hancock County, IL for Sunflower?

Hancock County sits in USDA Zone 6a. Sunflower grows reliably in zones 2a through 11b, so it's a good fit here.

Can Sunflower grow in Hancock County's climate?

Yes — Sunflower grows well in Hancock County's temperate climate. Hancock County averages a 187-day frost-free season, with last frost around April 14 and first frost around October 18.

🌱

Your Hancock County Garden Planner — Free

A 22-page printable planner built for Hancock 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 Hancock County, IL. Local conditions may vary. Last updated: August 2026.

Sources & credits

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