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When to plant Ageratum in Glynn County, GA

Plant Ageratum in Glynn County after February 9; the prime window is January 26–February 16.

When to Plant Ageratum in Glynn County, GA

Glynn County, Georgia Zone 9a June

This month in Glynn County, Georgia

A quick June briefing for Glynn County, Georgia gardeners — what's urgent, what's next, and what can wait.

Avg. last frost February 9
Avg. first frost December 13
Soil temp (4") 88°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Harvest ageratum as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Before July arrives, get these ready
  • First harvests: ageratum

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Ageratum (Ageratum houstonianum), the floss flower, produces clusters of fluffy, powder-puff blooms in the rare sky-blue and lavender tones difficult to find among warm-season annuals. Compact mounding habit makes it ideal as a front-of-border edging plant. Blooms from early summer through fall with minimal deadheading; heat and humidity tolerant once established.

Glynn County, Georgia is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 13, giving you a growing season of approximately 307 days.

At an elevation of 135 feet, Glynn County receives approximately 55.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Ageratum may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Ageratum will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Ageratum root diseases.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Glynn County, GA (Zone 9a) Year-round
307 days
Last Spring Frost February 9
307 growing days
First Fall Frost December 13

Glynn County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.9-6.2

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (102 days to spare)
Start indoors: Dec 16 Transplant: Jan 13 🌸 Bloom: Mar 10 – Aug 25
Recommended (50%) ✓ Fits season (97 days to spare)
Start indoors: Dec 29 Transplant: Jan 26 🌸 Bloom: Mar 23 – Sep 7
Safe Start (90%) ✓ Fits season (81 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🌸 Bloom: Apr 20 – Oct 5

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 Glynn County

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

Soil pH

Your soil pH (4.9–6.2) is more acidic than Ageratum prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Glynn County warms quickly in spring but drains fast. Ageratum will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Ageratum.

Organic Matter

Organic matter is low (1.8%). Add 2-3 inches of compost before planting Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

6
successive plantings in your 307-day season

Sow every 6.9 weeks. Last sowing by Sep 29 to harvest before frost.

Ageratum Water Budget

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

Monthly Watering Guide for Ageratum

Ageratum needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Ageratum Needs Rainfall You Supplement Action
Jan 4.4" 0" ❄️ Dormant
Feb 4.3" 3.9" 0.4" 💧 Light watering
Mar 4.3" 4.6" 0" ✅ Rainfall sufficient
Apr 4.3" 4.7" 0" ✅ Rainfall sufficient
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.2" 0" ✅ Rainfall sufficient
Aug 4.3" 5.8" 0" ✅ Rainfall sufficient
Sep 4.3" 4.8" 0" ✅ Rainfall sufficient
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 4.3" 4.7" 0" ✅ Rainfall sufficient

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

Ageratum 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.

Ageratum needs ~1,536 GDD — county provides 7,007 GDD Excellent fit

Ageratum Planting Timeline — Glynn County, GA

Ageratum Planting Calendar

Activity When Date Range
Start Indoors December 29 Dec 29 – Jan 12
Transplant Outdoors January 26 Jan 26 – Feb 9
Direct Sow January 26 Jan 26 – Feb 16
Bloom March 23 Mar 23 – Sep 7

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Transplant Outdoors Direct Sow
February Transplant Outdoors Direct Sow
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September Bloom
October
November
December Start Indoors

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

307 days in Glynn County

Growing Tips for Ageratum in Glynn County

Direct sow Ageratum outdoors after February 09 in Glynn County when soil has warmed and frost danger has passed.

Sandy soil in Glynn County dries quickly — mulch Ageratum with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in Glynn County, provide afternoon shade for Ageratum and water deeply in the morning.

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

General growing tips

Start seeds indoors 6–8 weeks before last frost — do not cover seed; it needs light to germinate. Can be direct-sown after last frost once soil warms to 60°F. Transplant or thin to proper spacing after frost danger passes. Deadheading isn't strictly required but tidying spent clusters improves appearance. Provide consistent moisture; drought causes premature setting. Avoid deep shade — blooms best in full sun to light afternoon shade.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Ageratum in Glynn County, GA?

Glynn County is in Zone 9a with an average last frost of February 9. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Glynn County, GA?

Glynn County, Georgia is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 13.

When should I plant Ageratum in Glynn County, GA?

In Glynn County, GA, plant Ageratum after the last frost (around February 9) and before the first frost (around December 13). Best results when soil holds above 50°F.

What growing zone is Glynn County, GA for Ageratum?

Glynn County sits in USDA Zone 9a. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Glynn County's climate?

Yes — Ageratum grows well in Glynn County's temperate climate. Glynn County averages a 308-day frost-free season, with last frost around February 9 and first frost around December 13.

🌱

Your Glynn County Garden Planner — Free

A 22-page printable planner built for Glynn 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.

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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 Glynn County, GA. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.