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When to plant Cosmos in Jackson County, IN

Cosmos planted in Jackson County between April 12 and May 3 matures in 60–90 days — well before the October 20 first frost.

When to Plant Cosmos in Jackson County, IN

Cosmos (Cosmos bipinnatus) is an airy, feathery-foliaged cottage garden annual from Mexico that thrives on neglect. It produces delicate daisy-like blooms in shades of pink, white, and magenta from midsummer until frost. Cosmos is a prolific self-sower — once established in a garden it often returns year after year without replanting. Excellent habitat plant for beneficial insects.

Jackson County, Indiana is in USDA Zone 6b. The average last spring frost is April 12 and the first fall frost is October 20, giving you a growing season of approximately 191 days.

At an elevation of 1,250 feet, Jackson County receives approximately 33.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Jackson County, IN (Zone 6b) Moderate season
191 days
Last Spring Frost April 12
191 growing days
First Fall Frost October 20

Jackson County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cosmos Planting Timeline — Jackson County, IN

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 – Mar 29
Transplant Outdoors April 12 Apr 12 – Apr 26
Direct Sow April 12 Apr 12 – May 3
Bloom June 21 Jun 21 – Oct 4

Plant 0.3" deep · 12" apart · Rows 18" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Direct Sow
June Bloom
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

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: N/A

🗺️ USDA Zone

Zone 6b

📆 Growing Season

191 days in Jackson County

Growing Tips for Jackson County

Direct-sow after last frost; cosmos germinates readily at 65-80°F in 7-10 days. Avoid rich soil — excess fertility produces lush foliage at the expense of blooms. Cosmos tolerates poor, dry soil exceptionally well. Pinch seedlings at 8 inches to encourage branching. Self-sows freely; allow some seed heads to mature and drop for a no-fuss perennial effect in warm climates.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cosmos in Jackson County, IN?

Jackson County is in Zone 6b with an average last frost of April 12. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, IN?

Jackson County, Indiana is in USDA Hardiness Zone 6b. The average last spring frost is April 12 and first fall frost is October 20.

When should I plant Cosmos in Jackson County, IN?

In Jackson County, IN, plant Cosmos after the last frost (around April 12) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Jackson County, IN for Cosmos?

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

Can Cosmos grow in Jackson County's climate?

Yes — Cosmos grows well in Jackson County's temperate climate. Jackson County averages a 191-day frost-free season, with last frost around April 12 and first frost around October 20.

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Your Jackson County Garden Planner — Free

A 22-page printable planner built for Jackson 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 Jackson County, IN. Local conditions may vary. Last updated: June 2026.

Sources & credits

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