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When to plant Ageratum in Indian River County County,

In Zone 10a (Indian River County County), direct-sow Ageratum between December 22 and January 12 for spring, after the January 26 last-frost mark.

When to Plant Ageratum in Indian River County, FL

Indian River County, Florida Zone 10a June

Your June gardening checklist

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

Avg. last frost January 26
Avg. first frost December 20
Soil temp (4") 89°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Start harvesting ageratum

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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.

Indian River County, Florida is in USDA Zone 10a. The average last spring frost is January 26 and the first fall frost is December 20, giving you a growing season of approximately 328 days.

At an elevation of 317 feet, Indian River County receives approximately 52.7 inches of rainfall annually with predominantly sand 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
Indian River County, FL (Zone 10a) Year-round
328 days
Last Spring Frost January 26
328 growing days
First Fall Frost December 20
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Indian River County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.2

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (109 days to spare)
Start indoors: Dec 8 Transplant: Dec 15 🌸 Bloom: Feb 9 – Aug 24
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Dec 15 Transplant: Dec 22 🌸 Bloom: Feb 16 – Aug 31
Safe Start (90%) ✓ Fits season (92 days to spare)
Start indoors: Jan 7 Transplant: Jan 14 🌸 Bloom: Mar 11 – Sep 23

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 Indian River County

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

Soil pH

Your soil pH (5.2–6.2) is more acidic than Ageratum prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.5%). 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 328-day season

Sow every 6.9 weeks. Last sowing by Oct 06 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 1,150 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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" 2.5" 1.8" 💧 Light watering
Feb 4.3" 2.5" 1.8" 💧 Light watering
Mar 4.3" 2.8" 1.5" 💧 Light watering
Apr 4.3" 2.5" 1.8" 💧 Light watering
May 4.3" 3.3" 1" 💧 Light watering
Jun 4.3" 7.8" 0" ✅ Rainfall sufficient
Jul 4.3" 7.2" 0" ✅ Rainfall sufficient
Aug 4.3" 8.2" 0" ✅ Rainfall sufficient
Sep 4.3" 7.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.4" 0" ✅ Rainfall sufficient
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 4.3" 1.9" 2.4" 🚿 Regular watering

Water needs are for active growing months only (Jan–Dec in Indian River 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 7,484 GDD Excellent fit

Ageratum Planting Timeline — Indian River County, FL

Ageratum Planting Calendar

Activity When Date Range
Start Indoors December 15 Dec 15 – Dec 29
Transplant Outdoors December 22 Dec 22 – Jan 5
Direct Sow December 22 Dec 22 – Jan 12
Bloom February 16 Feb 16 – Aug 31

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors Direct Sow
February Bloom
March Bloom
April Bloom
May Bloom
June Bloom
July Bloom
August Bloom
September
October
November
December Start Indoors Transplant Outdoors Direct Sow
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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 10a

📆 Growing Season

328 days in Indian River County

Growing Tips for Ageratum in Indian River County

Direct sow Ageratum outdoors after January 26 in Indian River County when soil has warmed and frost danger has passed.

Sandy soil in Indian River 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 Indian River 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 Indian River County, FL?

Indian River County is in Zone 10a with an average last frost of January 26. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Indian River County, FL?

Indian River County, Florida is in USDA Hardiness Zone 10a. The average last spring frost is January 26 and first fall frost is December 20.

When should I plant Ageratum in Indian River County, ?

In Indian River County, , plant Ageratum after the last frost (around January 26) and before the first frost (around December 20). Best results when soil holds above 50°F.

What growing zone is Indian River County, for Ageratum?

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

Can Ageratum grow in Indian River County's climate?

Yes — Ageratum grows well in Indian River County's temperate climate. Indian River County averages a 329-day frost-free season, with last frost around January 26 and first frost around December 20.

🌱

Your Indian River County Garden Planner — Free

A 22-page printable planner built for Indian River County (Zone 10a). 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 Indian River County, FL. 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.