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When to Plant Ageratum in Erath County, TX

Erath County, Texas Zone 8b June

June to-do list for Erath County, Texas

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

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 14.1 hrs
  1. Start harvesting ageratum

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

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.

Erath County, Texas is in USDA Zone 8b. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 1,968 feet, Erath County receives approximately 55.9 inches of rainfall annually with predominantly clay soil. Summer highs average 92°F, providing good warmth for Ageratum during the growing season. Clay soil retains moisture well for Ageratum, but amend with compost to improve drainage and prevent root rot. 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
Erath County, TX (Zone 8b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

Erath County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.7

Drainage

Well Drained

Ageratum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 2 Transplant: Mar 2 🌸 Bloom: Apr 27 – Sep 28
Recommended (50%) ✓ Fits season (35 days to spare)
Start indoors: Feb 11 Transplant: Mar 11 🌸 Bloom: May 6 – Oct 7
Safe Start (90%) ✓ Fits season (28 days to spare)
Start indoors: Mar 4 Transplant: Apr 1 🌸 Bloom: May 27 – Oct 28

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 Erath County

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

Soil pH

Your soil pH (7.3–7.7) is more alkaline than Ageratum prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (46% clay) in Erath County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Ageratum.

How to Plant Ageratum

8"
Between Plants
10"
Between Rows

Succession Planting Ageratum

4
successive plantings in your 231-day season

Sow every 6.9 weeks. Last sowing by Aug 28 to harvest before frost.

Ageratum Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.6" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 5.8" 0" ✅ Rainfall sufficient
May 4.3" 7.2" 0" ✅ Rainfall sufficient
Jun 4.3" 8.1" 0" ✅ Rainfall sufficient
Jul 4.3" 8.1" 0" ✅ Rainfall sufficient
Aug 4.3" 6.7" 0" ✅ Rainfall sufficient
Sep 4.3" 5.9" 0" ✅ Rainfall sufficient
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 2" 2.3" 🚿 Regular watering
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Erath 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 ~1,282 GDD — county provides 4,389 GDD Excellent fit

Ageratum Planting Timeline — Erath County, TX

Ageratum Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors March 11 Mar 11 – Mar 25
Direct Sow March 11 Mar 11 – Apr 1
Bloom May 6 May 6 – Oct 7

· 8" apart · Rows 10" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April 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

1"/week · Natural rainfall sufficient

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

231 days in Erath County

Growing Tips for Ageratum in Erath County

Direct sow Ageratum outdoors after March 25 in Erath County when soil has warmed and frost danger has passed.

With Erath County's clay soil (46% clay), work in 3-4 inches of compost before planting Ageratum. Avoid tilling when soil is wet to prevent compaction.

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 Erath County, TX?

Erath County is in Zone 8b with an average last frost of March 25. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Erath County, TX?

Erath County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 25 and first fall frost is November 11.

🌱

Your Erath County Garden Planner — Free

A 22-page printable planner built for Erath 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 Erath County, TX. 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.