When to plant Cosmos in Dunklin County, MO
Cosmos planted in Dunklin County between March 20 and April 10 matures in 60–90 days — well before the November 2 first frost.
When to Plant Cosmos in Dunklin County, MO
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.
Dunklin County, Missouri is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is November 2, giving you a growing season of approximately 220 days.
At an elevation of 1,344 feet, Dunklin County receives approximately 33.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 94°F, providing good warmth for Cosmos during the growing season.
Dunklin County Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-7.1
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Jun | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Aug | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Nov | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Dec | — | 1.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Dunklin County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos Planting Timeline — Dunklin County, MO
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 27 | Feb 27 – Mar 13 |
| Transplant Outdoors | March 20 | Mar 20 – Apr 3 |
| Direct Sow | March 20 | Mar 20 – Apr 10 |
| Bloom | May 29 | May 29 – Oct 2 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Start Indoors Transplant Outdoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Bloom |
| 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 7b
📆 Growing Season
220 days in Dunklin County
Growing Tips for Dunklin 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 Dunklin County, MO?
Dunklin County is in Zone 7b with an average last frost of March 27. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dunklin County, MO?
Dunklin County, Missouri is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is November 2.
When should I plant Cosmos in Dunklin County, MO?
In Dunklin County, MO, plant Cosmos after the last frost (around March 27) and before the first frost (around November 2). Best results when soil holds above 50°F.
What growing zone is Dunklin County, MO for Cosmos?
Dunklin County sits in USDA Zone 7b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Dunklin County's climate?
Yes — Cosmos grows well in Dunklin County's temperate climate. Dunklin County averages a 220-day frost-free season, with last frost around March 27 and first frost around November 2.
Your Dunklin County Garden Planner — Free
A 22-page printable planner built for Dunklin County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.