When to plant Cosmos in Chatham County, GA
Aim to plant Cosmos in Chatham County on or after February 5; the window stays open through February 26. Chatham County's 263-day frost-free season gives you plenty of room for a spring and fall cycle.
When to Plant Cosmos in Chatham County, GA
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.
Chatham County, Georgia is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 23, giving you a growing season of approximately 263 days.
At an elevation of 398 feet, Chatham County receives approximately 51.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Cosmos during the growing season. Sandy soil warms quickly in spring — great for early planting — but Cosmos will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.
Chatham County Soil Profile
Soil Type
Sandy Loam
Soil pH
5-6.1
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 | — | 4.3" | 0" | ❄️ Dormant |
| Feb | — | 4.4" | 0" | ❄️ Dormant |
| Mar | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Apr | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| May | 4.3" | 4.2" | 0.1" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Oct | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| Nov | 4.3" | 4" | 0.3" | 💧 Light watering |
| Dec | — | 4.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Chatham County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Cosmos Planting Timeline — Chatham County, GA
Cosmos Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 5 | Feb 5 – Feb 19 |
| Transplant Outdoors | February 5 | Feb 5 – Feb 19 |
| Direct Sow | February 5 | Feb 5 – Feb 26 |
| Bloom | April 16 | Apr 16 – Oct 1 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| 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 9a
📆 Growing Season
263 days in Chatham County
Growing Tips for Chatham 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 Chatham County, GA?
Chatham County is in Zone 9a with an average last frost of March 5. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.
What planting zone is Chatham County, GA?
Chatham County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 23.
When should I plant Cosmos in Chatham County, GA?
In Chatham County, GA, plant Cosmos after the last frost (around March 5) and before the first frost (around November 23). Best results when soil holds above 50°F.
What growing zone is Chatham County, GA for Cosmos?
Chatham County sits in USDA Zone 9a. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.
Can Cosmos grow in Chatham County's climate?
Yes — Cosmos grows well in Chatham County's temperate climate. Chatham County averages a 263-day frost-free season, with last frost around March 5 and first frost around November 23.
Your Chatham County Garden Planner — Free
A 22-page printable planner built for Chatham County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.