When to Plant Ageratum in Bexar 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.
Bexar County, Texas is in USDA Zone 9a. The average last spring frost is March 11 and the first fall frost is November 17, giving you a growing season of approximately 251 days.
At an elevation of 3,197 feet, Bexar County receives approximately 52.1 inches of rainfall annually with predominantly loam soil. Summer highs average 93°F, providing good warmth for Ageratum during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Ageratum root diseases.
Bexar County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.8
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Apr | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 7.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.2" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 6.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 4.9" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Nov | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Bexar County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Ageratum Planting Timeline — Bexar County, TX
Ageratum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 28 | Jan 28 – Feb 11 |
| Transplant Outdoors | February 25 | Feb 25 – Mar 11 |
| Direct Sow | February 25 | Feb 25 – Mar 18 |
| Bloom | April 22 | Apr 22 – Oct 7 |
· 8" apart · Rows 10" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 | 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 9a
📆 Growing Season
251 days in Bexar County
Growing Tips for Bexar 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 →
Ageratum in Other Locations
Frequently Asked Questions
When should I plant Ageratum in Bexar County, TX?
Bexar County is in Zone 9a with an average last frost of March 11. Plan your Ageratum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Bexar County, TX?
Bexar County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 11 and first fall frost is November 17.
Your Bexar County Garden Planner — Free
A 22-page printable planner built for Bexar 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.