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When to plant Ageratum in Collier County, FL

Aim to plant Ageratum in Collier County on or after December 1; the window stays open through December 22. Collier County's 365-day frost-free season gives you plenty of room for a spring and fall cycle.

When to Plant Ageratum in Collier County, FL

Collier County, Florida Zone 10b July

Top priorities for Collier County, Florida gardeners in July

A quick July briefing for Collier County, Florida gardeners — what's urgent, what's next, and what can wait.

Avg. last frost January 12
Soil temp (4") 95°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Start harvesting ageratum

    If you can't use it all right away, check the food-preservation section of your planner.

Get ahead of August
  • 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.

Collier County, Florida is in USDA Zone 10b. The average last spring frost is January 12 and the first fall frost is April 15, giving you a growing season of approximately 93 days.

At an elevation of 185 feet, Collier County receives approximately 61.3 inches of rainfall annually with predominantly sand soil. Summer highs average 85°F, providing good warmth for Ageratum during the growing season. 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
Collier County, FL (Zone 10b) Very short season
93 days
Last Spring Frost January 12
93 growing days
First Fall Frost April 15

Collier County Soil Profile

Soil Type

Sand

Soil pH

5-6.2

Drainage

Well Drained

Soil Compatibility in Collier County

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Ageratum prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Collier 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 (1.3%). Add 2-3 inches of compost before planting Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 1,932 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 4.3" 2.8" 1.5" 💧 Light watering
Feb 4.3" 3.3" 1" 💧 Light watering
Mar 4.3" 4.1" 0.2" 💧 Light watering
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 7.5" 0" ✅ Rainfall sufficient
Jul 4.3" 10" 0" ✅ Rainfall sufficient
Aug 4.3" 9" 0" ✅ Rainfall sufficient
Sep 4.3" 8.4" 0" ✅ Rainfall sufficient
Oct 4.3" 5.6" 0" ✅ Rainfall sufficient
Nov 2.3" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jan–Oct in Collier 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 ~928 GDD — county provides 5,018 GDD Excellent fit

Ageratum Planting Timeline — Collier County, FL

Ageratum Planting Calendar

Activity When Date Range
Start Indoors December 1 Dec 1 – Dec 15
Transplant Outdoors December 1 Dec 1 – Dec 15
Direct Sow December 1 Dec 1 – Dec 22
Bloom January 26 Jan 26 – Aug 24

· 8" apart · Rows 10" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 10b

📆 Growing Season

93 days in Collier County

Growing Tips for Ageratum in Collier County

Direct sow Ageratum outdoors after January 12 in Collier County when soil has warmed and frost danger has passed.

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

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 Collier County, FL?

Collier County is in Zone 10b with an average last frost of January 12. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Collier County, FL?

Collier County, Florida is in USDA Hardiness Zone 10b. The average last spring frost is January 12 and first fall frost is .

When should I plant Ageratum in Collier County, FL?

In Collier County, FL, plant Ageratum after the last frost (around January 1) and before the first frost (around December 31). Best results when soil holds above 50°F.

What growing zone is Collier County, FL for Ageratum?

Collier County sits in USDA Zone 10b. Ageratum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Ageratum grow in Collier County's climate?

Yes — Ageratum grows well in Collier County's temperate climate. Collier County averages a 365-day frost-free season, with last frost around January 1 and first frost around December 31.

🌱

Your Collier County Garden Planner — Free

A 22-page printable planner built for Collier County (Zone 10b). 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 Collier County, FL. Local conditions may vary. Last updated: July 2026.

Sources & credits

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