When to plant Cosmos in Barton County, KS
Cosmos planted in Barton County between April 20 and May 11 matures in 60–90 days — well before the October 16 first frost.
When to Plant Cosmos in Barton County, KS
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.
Barton County, Kansas is in USDA Zone 6b. The average last spring frost is April 20 and the first fall frost is October 16, giving you a growing season of approximately 179 days.
At an elevation of 638 feet, Barton County receives approximately 25.9 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Cosmos during the growing season.
Barton County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.3
Drainage
Well Drained
Monthly Watering Guide for Cosmos
Cosmos needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Cosmos Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.7" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 1.5" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| May | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jul | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | — | 0.9" | 0" | ❄️ Dormant |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Barton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos Planting Timeline — Barton County, KS
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | April 20 | Apr 20 – May 4 |
| Direct Sow | April 20 | Apr 20 – May 11 |
| Bloom | June 29 | Jun 29 – Oct 12 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors 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
179 days in Barton County
Growing Tips for Barton 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 Barton County, KS?
Barton County is in Zone 6b with an average last frost of April 20. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Barton County, KS?
Barton County, Kansas is in USDA Hardiness Zone 6b. The average last spring frost is April 20 and first fall frost is October 16.
When should I plant Cosmos in Barton County, KS?
In Barton County, KS, plant Cosmos after the last frost (around April 20) and before the first frost (around October 16). Best results when soil holds above 50°F.
What growing zone is Barton County, KS for Cosmos?
Barton 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 Barton County's climate?
Yes — Cosmos grows well in Barton County's temperate climate. Barton County averages a 179-day frost-free season, with last frost around April 20 and first frost around October 16.
Your Barton County Garden Planner — Free
A 22-page printable planner built for Barton 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.