When to Plant Rosemary in Harris County, TX
Rosemary is an aromatic evergreen shrub with needle-like leaves and a piney, citrus flavor. It is a Mediterranean herb that thrives in warm, dry conditions.
Harris County, Texas is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 4, giving you a growing season of approximately 293 days.
At an elevation of 390 feet, Harris County receives approximately 67.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 102°F, so Rosemary may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Rosemary will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.
Harris County Soil Profile
Soil Type
Sandy Loam
Soil pH
5.3-6.5
Drainage
Well Drained
Monthly Watering Guide for Rosemary
Rosemary needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Rosemary Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Mar | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Apr | 4.3" | 7.4" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 10.1" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 10" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 9.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.5" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.3" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Nov | 4.3" | 2.2" | 2.1" | 💧 Light watering |
| Dec | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in Harris County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary Planting Timeline — Harris County, TX
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | February 21 | Feb 21 – Mar 7 |
| Harvest | May 16 | May 16 – Oct 3 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 9a
📆 Growing Season
293 days in Harris County
Growing Tips for Harris County
Grow in well-drained soil and avoid overwatering. In cold climates, grow in containers and bring indoors for winter. Propagate from stem cuttings for faster results than seed.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Rosemary in Other Locations
Frequently Asked Questions
When should I plant Rosemary in Harris County, TX?
Harris County is in Zone 9a with an average last frost of February 14. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Harris County, TX?
Harris County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 4.
Plan Your Garden with Confidence
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