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When to plant Ageratum in Mobile County, AL

Ageratum planted in Mobile County between February 17 and March 10 matures in 60–75 days — well before the November 24 first frost.

When to Plant Ageratum in Mobile County, AL

Mobile County, Alabama Zone 9a June

Your June planting checklist for Mobile County, Alabama

June rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Mobile County, Alabama.

Avg. last frost March 3
Avg. first frost November 24
Soil temp (4") 81°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for ageratum

    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: 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.

Mobile County, Alabama is in USDA Zone 9a. The average last spring frost is March 3 and the first fall frost is November 24, giving you a growing season of approximately 266 days.

At an elevation of 101 feet, Mobile County receives approximately 48.3 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.

Annual Blooms in Multi-season Pollinator-friendly Good for cutting
Mobile County, AL (Zone 9a) Long season
266 days
Last Spring Frost March 3
266 growing days
First Fall Frost November 24

Mobile County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (61 days to spare)
Start indoors: Jan 8 Transplant: Feb 5 🌸 Bloom: Apr 2 – Sep 17
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Jan 20 Transplant: Feb 17 🌸 Bloom: Apr 14 – Sep 29
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🌸 Bloom: May 1 – Oct 16

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 Mobile County

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

Soil pH

Your soil pH (4.8–6.1) is more acidic than Ageratum prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Mobile 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 moderate (2.2%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

5
successive plantings in your 266-day season

Sow every 6.9 weeks. Last sowing by Sep 10 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 3.7" 0" ❄️ Dormant
Feb 3.5" 0" ❄️ Dormant
Mar 4.3" 4.9" 0" ✅ Rainfall sufficient
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 4" 0.3" 💧 Light watering
Jul 4.3" 5.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.2" 0.1" 💧 Light watering
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.5" 0.8" 💧 Light watering
Nov 4.3" 4.3" 0" ✅ Rainfall sufficient
Dec 4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Mobile 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 6,051 GDD Excellent fit

Ageratum Planting Timeline — Mobile County, AL

Ageratum Planting Calendar

Activity When Date Range
Start Indoors January 20 Jan 20 – Feb 3
Transplant Outdoors February 17 Feb 17 – Mar 3
Direct Sow February 17 Feb 17 – Mar 10
Bloom April 14 Apr 14 – Sep 29

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

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

266 days in Mobile County

Growing Tips for Ageratum in Mobile County

Direct sow Ageratum outdoors after March 03 in Mobile County when soil has warmed and frost danger has passed.

Sandy soil in Mobile 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 Mobile 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 Mobile County, AL?

Mobile County is in Zone 9a with an average last frost of March 3. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Mobile County, AL?

Mobile County, Alabama is in USDA Hardiness Zone 9a. The average last spring frost is March 3 and first fall frost is November 24.

When should I plant Ageratum in Mobile County, AL?

In Mobile County, AL, plant Ageratum after the last frost (around March 3) and before the first frost (around November 24). Best results when soil holds above 50°F.

What growing zone is Mobile County, AL for Ageratum?

Mobile 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 Mobile County's climate?

Yes — Ageratum grows well in Mobile County's temperate climate. Mobile County averages a 266-day frost-free season, with last frost around March 3 and first frost around November 24.

🌱

Your Mobile County Garden Planner — Free

A 22-page printable planner built for Mobile 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 Mobile County, AL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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