Blog

When to plant Cosmos in Rowan County, KY

Aim to plant Cosmos in Rowan County on or after April 16; the window stays open through May 7. Rowan County's 191-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Cosmos in Rowan County, KY

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.

Rowan County, Kentucky is in USDA Zone 6b. The average last spring frost is April 16 and the first fall frost is October 24, giving you a growing season of approximately 191 days.

At an elevation of 2,014 feet, Rowan County receives approximately 49 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Cosmos during the growing season.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Rowan County, KY (Zone 6b) Moderate season
191 days
Last Spring Frost April 16
191 growing days
First Fall Frost October 24

Rowan County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Cosmos Planting Timeline — Rowan County, KY

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 16 Apr 16 – Apr 30
Direct Sow April 16 Apr 16 – May 7
Bloom June 25 Jun 25 – Oct 8

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors 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 Rowan County

Growing Tips for Rowan 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 Rowan County, KY?

Rowan County is in Zone 6b with an average last frost of April 16. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rowan County, KY?

Rowan County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 16 and first fall frost is October 24.

When should I plant Cosmos in Rowan County, KY?

In Rowan County, KY, plant Cosmos after the last frost (around April 16) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Rowan County, KY for Cosmos?

Rowan 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 Rowan County's climate?

Yes — Cosmos grows well in Rowan County's temperate climate. Rowan County averages a 191-day frost-free season, with last frost around April 16 and first frost around October 24.

🌱

Your Rowan County Garden Planner — Free

A 22-page printable planner built for Rowan 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Rowan County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.