When to Plant Ageratum in Howard 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.
Howard County, Texas is in USDA Zone 8a. The average last spring frost is March 26 and the first fall frost is November 12, giving you a growing season of approximately 231 days.
At an elevation of 3,918 feet, Howard County receives approximately 59.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 99°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.
Howard County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Ageratum Planting Timeline — Howard County, TX
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | February 12 | Feb 12 – Feb 26 |
| Transplant Outdoors | March 19 | Mar 19 – Apr 2 |
| Direct Sow | March 19 | Mar 19 – Apr 9 |
| Bloom | May 14 | May 14 – Oct 1 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Transplant Outdoors 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
Moderate — regular watering
📅 Days to Maturity
60–75 days
🧪 Soil pH
Needs 6–7 · Your soil: N/A
🗺️ USDA Zone
Zone 8a
📆 Growing Season
231 days in Howard County
Growing Tips for Howard 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
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Ageratum in Other Locations
Frequently Asked Questions
When should I plant Ageratum in Howard County, TX?
Howard County is in Zone 8a with an average last frost of March 26. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Howard County, TX?
Howard County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 26 and first fall frost is November 12.
Your Howard County Garden Planner — Free
A 22-page printable planner built for Howard County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.