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When to Plant Ageratum in Jasper County, TX

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.

Jasper County, Texas is in USDA Zone 9a. The average last spring frost is March 3 and the first fall frost is November 22, giving you a growing season of approximately 264 days.

At an elevation of 97 feet, Jasper County receives approximately 71.8 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
Jasper County, TX (Zone 9a) Long season
264 days
Last Spring Frost March 3
264 growing days
First Fall Frost November 22

Jasper County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.3-6.5

Drainage

Well Drained

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 2.7" 0" ❄️ Dormant
Mar 4.3" 4.2" 0.1" 💧 Light watering
Apr 4.3" 7.3" 0" ✅ Rainfall sufficient
May 4.3" 10.8" 0" ✅ Rainfall sufficient
Jun 4.3" 12.7" 0" ✅ Rainfall sufficient
Jul 4.3" 7.8" 0" ✅ Rainfall sufficient
Aug 4.3" 8.4" 0" ✅ Rainfall sufficient
Sep 4.3" 7.2" 0" ✅ Rainfall sufficient
Oct 4.3" 4.9" 0" ✅ Rainfall sufficient
Nov 4.3" 2.3" 2" 💧 Light watering
Dec 1.8" 0" ❄️ Dormant

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

Ageratum Planting Timeline — Jasper County, TX

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

Moderate — regular watering

📅 Days to Maturity

60–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

264 days in Jasper County

Growing Tips for Jasper County

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 Jasper County, TX?

Jasper 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 Jasper County, TX?

Jasper County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 3 and first fall frost is November 22.

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Your Jasper County Garden Planner — Free

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

Sources & credits

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