When to Plant Salvia in Robertson County, TX
Salvia splendens is a tender perennial from Brazil grown as a warm-season annual throughout the US. Its vivid, upright flower spikes in brilliant red, purple, and coral are irresistible to hummingbirds, bees, and butterflies. One of the longest-blooming annuals in the landscape — plants bloom from early summer until hard frost with minimal deadheading required.
Robertson County, Texas is in USDA Zone 9a. The average last spring frost is March 7 and the first fall frost is November 16, giving you a growing season of approximately 254 days.
At an elevation of 85 feet, Robertson County receives approximately 61.1 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Salvia during the growing season. Clay soil retains moisture well for Salvia, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Salvia root diseases.
Robertson County Soil Profile
Soil Type
Clay
Soil pH
6.0-7.0
Drainage
Well Drained
Salvia Planting Timeline — Robertson County, TX
Salvia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 10 | Jan 10 – Jan 24 |
| Transplant Outdoors | February 14 | Feb 14 – Feb 28 |
| Bloom | April 25 | Apr 25 – Oct 10 |
· 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors |
| March | — |
| 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
70–90 days
🧪 Soil pH
Needs 5.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 9a
📆 Growing Season
254 days in Robertson County
Growing Tips for Robertson County
Start indoors 8-10 weeks before last frost; seeds need 65-70°F soil and light to germinate (surface-sow, do not cover). Transplant after last frost when soil has warmed. Salvia is frost-sensitive — even a light frost kills plants. Pinch spent spikes to encourage continued bloom. Tolerates heat and humidity well once established. In zones 9b-11b can be grown as a short-lived perennial.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Salvia in Other Locations
Frequently Asked Questions
When should I plant Salvia in Robertson County, TX?
Robertson County is in Zone 9a with an average last frost of March 7. Plan your Salvia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Robertson County, TX?
Robertson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 7 and first fall frost is November 16.
Your Robertson County Garden Planner — Free
A 22-page printable planner built for Robertson 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.