When to Plant Rosemary in Hays County, TX
Hays County, Texas gardeners: here's your May plan
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
Looking ahead to June
- First harvests: rosemary
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.
Hays County, Texas is in USDA Zone 9a. The average last spring frost is March 6 and the first fall frost is November 22, giving you a growing season of approximately 261 days.
At an elevation of 3,119 feet, Hays County receives approximately 61.8 inches of rainfall annually with predominantly clay soil. Summer highs average 90°F, providing good warmth for Rosemary during the growing season. Clay soil retains moisture well for Rosemary, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.
Hays County Soil Profile
Soil Type
Clay
Soil pH
7-8
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Hays County
How your county's soil matches Rosemary's growing requirements.
Soil pH
Your soil pH (7.0–8.0) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.
Soil Texture
Heavy clay soil (45% clay) in Hays County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Rosemary.
How to Plant Rosemary
Succession Planting Rosemary
Sow every 9.1 weeks. Last sowing by May 26 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Rosemary
Rosemary needs approximately 0.3 inches of water per week (1.3" 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 | — | 2.3" | 0" | ❄️ Dormant |
| Mar | 1.3" | 3.5" | 0" | ✅ Rainfall sufficient |
| Apr | 1.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| May | 1.3" | 9.5" | 0" | ✅ Rainfall sufficient |
| Jun | 1.3" | 9.8" | 0" | ✅ Rainfall sufficient |
| Jul | 1.3" | 7" | 0" | ✅ Rainfall sufficient |
| Aug | 1.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Sep | 1.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Oct | 1.3" | 4.2" | 0" | ✅ Rainfall sufficient |
| Nov | 1.3" | 2.3" | 0" | ✅ Rainfall sufficient |
| Dec | — | 1.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Hays County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Rosemary Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Rosemary Planting Timeline — Hays County, TX
Rosemary Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Transplant Outdoors | March 13 | Mar 13 – Mar 27 |
| Harvest | June 5 | Jun 5 – Oct 23 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Transplant Outdoors |
| April | — |
| May | — |
| June | Harvest |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.3"/week · Natural rainfall sufficient
📅 Days to Maturity
80–180 days
🧪 Soil pH
Needs 6–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
261 days in Hays County
Growing Tips for Rosemary in Hays County
Direct sow Rosemary outdoors after March 06 in Hays County when soil has warmed and frost danger has passed.
With Hays County's clay soil (45% clay), work in 3-4 inches of compost before planting Rosemary. Avoid tilling when soil is wet to prevent compaction.
With 62" of annual rainfall in Hays County, ensure good drainage for Rosemary — excess moisture can promote root rot and fungal diseases.
General growing tips
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 Hays County, TX?
Hays County is in Zone 9a with an average last frost of March 6. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.
What planting zone is Hays County, TX?
Hays County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 6 and first fall frost is November 22.
Your Hays County Garden Planner — Free
A 24-page printable planner built for Hays 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.