When to plant Cosmos in Clark County, IN
The best window to plant Cosmos in Clark County, is April 10–May 1, when soil warms to 50°F. Last frost typically hits April 10; first frost October 22.
When to Plant Cosmos in Clark 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.
Clark County, Indiana is in USDA Zone 7a. The average last spring frost is April 10 and the first fall frost is October 22, giving you a growing season of approximately 195 days.
At an elevation of 1,265 feet, Clark County receives approximately 36.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Cosmos during the growing season.
Clark County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Cosmos Planting Timeline — Clark County, IN
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 13 | Mar 13 – Mar 27 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | April 10 | Apr 10 – May 1 |
| Bloom | June 19 | Jun 19 – Oct 9 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 7a
📆 Growing Season
195 days in Clark County
Growing Tips for Clark 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 →
Cosmos in Other Locations
Frequently Asked Questions
When should I plant Cosmos in Clark County, IN?
Clark County is in Zone 7a with an average last frost of April 10. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, IN?
Clark County, Indiana is in USDA Hardiness Zone 7a. The average last spring frost is April 10 and first fall frost is October 22.
When should I plant Cosmos in Clark County, IN?
In Clark County, IN, plant Cosmos after the last frost (around April 10) and before the first frost (around October 22). Best results when soil holds above 50°F.
What growing zone is Clark County, IN for Cosmos?
Clark County sits in USDA Zone 7a. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Clark County's climate?
Yes — Cosmos grows well in Clark County's temperate climate. Clark County averages a 195-day frost-free season, with last frost around April 10 and first frost around October 22.
Your Clark County Garden Planner — Free
A 22-page printable planner built for Clark County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.