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When to plant Cosmos in Greene County, GA

In Greene County, plant Cosmos in spring between March 18 and April 8, once soil temps hold above 50°F. Greene County's last frost averages April 8, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 60–90 days before the first frost on October 31.

When to Plant Cosmos in Greene County, GA

Greene County, Georgia Zone 8b June

Greene County, Georgia gardeners: here's your June plan

Each item below is timed to Greene County, Georgia's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 8
Avg. first frost October 31
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 14.2 hrs
  1. Collect cosmos at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

To set up a strong July, finish these tasks
  • First harvests: cosmos

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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.

Greene County, Georgia is in USDA Zone 8b. The average last spring frost is April 8 and the first fall frost is October 31, giving you a growing season of approximately 206 days.

At an elevation of 60 feet, Greene County receives approximately 52.6 inches of rainfall annually with predominantly clay loam soil. Summer highs average 88°F, providing good warmth for Cosmos during the growing season. Clay soil retains moisture well for Cosmos, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cosmos root diseases.

Annual Blooms in Summer Pollinator-friendly Good for cutting
Greene County, GA (Zone 8b) Long season
206 days
Last Spring Frost April 8
206 growing days
First Fall Frost October 31

Greene County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.5

Drainage

Well Drained

Cosmos Planting Risk Windows

Early Start (70% safe) ✓ Fits season (4 days to spare)
Start indoors: Mar 2 Transplant: Mar 9 🌸 Bloom: May 18 – Oct 19
Recommended (50%) ✓ Fits season (3 days to spare)
Start indoors: Mar 11 Transplant: Mar 18 🌸 Bloom: May 27 – Oct 28
Safe Start (90%) ✓ Fits season (4 days to spare)
Start indoors: Mar 25 Transplant: Apr 1 🌸 Bloom: Jun 10 – Nov 11

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Greene County

How your county's soil matches Cosmos's growing requirements.

Soil pH

Your soil pH (5.4–6.5) is more acidic than Cosmos prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Greene County is excellent for Cosmos — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Cosmos.

How to Plant Cosmos

0.3"
Planting Depth
12"
Between Plants
18"
Between Rows

Succession Planting Cosmos

4
successive plantings in your 206-day season

Sow every 6.9 weeks. Last sowing by Aug 02 to harvest before frost.

Cosmos Water Budget

Plant needs
0.5″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Cosmos

Cosmos needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Cosmos Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 2.2" 4.3" 0" ✅ Rainfall sufficient
May 2.2" 3.8" 0" ✅ Rainfall sufficient
Jun 2.2" 4.6" 0" ✅ Rainfall sufficient
Jul 2.2" 5.7" 0" ✅ Rainfall sufficient
Aug 2.2" 5.4" 0" ✅ Rainfall sufficient
Sep 2.2" 4.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3.1" 0" ✅ Rainfall sufficient
Nov 4" 0" ❄️ Dormant
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Greene County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Cosmos Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Cosmos needs ~1,200 GDD — county provides 3,296 GDD Excellent fit

Cosmos Planting Timeline — Greene County, GA

Cosmos Planting Calendar

Activity When Date Range
Start Indoors March 11 Mar 11 – Mar 25
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 18 Mar 18 – Apr 8
Bloom May 27 May 27 – Oct 28

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

Month-by-Month Timeline

MonthActivities
January
February
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

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

206 days in Greene County

Growing Tips for Cosmos in Greene County

Direct sow Cosmos outdoors after April 08 in Greene County when soil has warmed and frost danger has passed.

With Greene County's clay soil (29% clay), work in 3-4 inches of compost before planting Cosmos. Avoid tilling when soil is wet to prevent compaction.

Common pests for Cosmos in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

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 Greene County, GA?

Greene County is in Zone 8b with an average last frost of April 8. Plan your Cosmos planting based on this frost date — see the calendar above for exact timing.

What planting zone is Greene County, GA?

Greene County, Georgia is in USDA Hardiness Zone 8b. The average last spring frost is April 8 and first fall frost is October 31.

When should I plant Cosmos in Greene County, GA?

In Greene County, GA, plant Cosmos after the last frost (around April 8) and before the first frost (around October 31). Best results when soil holds above 50°F.

What growing zone is Greene County, GA for Cosmos?

Greene County sits in USDA Zone 8b. Cosmos grows reliably in zones 2a through 11b, so it's a good fit here.

Can Cosmos grow in Greene County's climate?

Yes — Cosmos grows well in Greene County's temperate climate. Greene County averages a 206-day frost-free season, with last frost around April 8 and first frost around October 31.

🌱

Your Greene County Garden Planner — Free

A 22-page printable planner built for Greene County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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