Blog

When to Plant Rosemary in Aransas County, TX

Aransas County, Texas Zone 9b May

May in Aransas County, Texas — your action list

Each item below is timed to Aransas County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 10
Avg. first frost December 12
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Harvest rosemary as they ripen

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

A few tasks this May that'll pay off in June
  • First harvests: rosemary

Instant PDF download. No spam, unsubscribe any time.

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.

Aransas County, Texas is in USDA Zone 9b. The average last spring frost is February 10 and the first fall frost is December 12, giving you a growing season of approximately 305 days.

At an elevation of 173 feet, Aransas County receives approximately 67.4 inches of rainfall annually with predominantly loam soil. Summer highs average 104°F, so Rosemary may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Rosemary root diseases.

Aransas County, TX (Zone 9b) Year-round
305 days
Last Spring Frost February 10
305 growing days
First Fall Frost December 12

Aransas County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Transplant: Jan 25 🍅 Harvest: Apr 19 – Sep 6
Recommended (50%) ✓ Fits season (74 days to spare)
Transplant: Feb 17 🍅 Harvest: May 12 – Sep 29
Safe Start (90%) ✓ Fits season (54 days to spare)
Transplant: Mar 18 🍅 Harvest: Jun 10 – Oct 28

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 Aransas County

How your county's soil matches Rosemary's growing requirements.

Soil pH

Your soil pH (6.7–7.7) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

The loam soil in Aransas County is excellent for Rosemary — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Rosemary.

How to Plant Rosemary

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Rosemary

4
successive plantings in your 305-day season

Sow every 9.1 weeks. Last sowing by Jun 15 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 1.9" 0" ❄️ Dormant
Feb 1.3" 2.4" 0" ✅ Rainfall sufficient
Mar 1.3" 4.3" 0" ✅ Rainfall sufficient
Apr 1.3" 6.7" 0" ✅ Rainfall sufficient
May 1.3" 10.1" 0" ✅ Rainfall sufficient
Jun 1.3" 12" 0" ✅ Rainfall sufficient
Jul 1.3" 8.2" 0" ✅ Rainfall sufficient
Aug 1.3" 8.7" 0" ✅ Rainfall sufficient
Sep 1.3" 5.4" 0" ✅ Rainfall sufficient
Oct 1.3" 3.9" 0" ✅ Rainfall sufficient
Nov 1.3" 2.2" 0" ✅ Rainfall sufficient
Dec 1.3" 1.7" 0" ✅ Rainfall sufficient

Water needs are for active growing months only (Feb–Dec in Aransas 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 needs ~3,640 GDD — county provides 8,568 GDD Excellent fit

Rosemary Planting Timeline — Aransas County, TX

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors February 17 Feb 17 – Mar 3
Harvest May 12 May 12 – Sep 29

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Transplant Outdoors
March Transplant Outdoors
April
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October
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 9b

📆 Growing Season

305 days in Aransas County

Growing Tips for Rosemary in Aransas County

Direct sow Rosemary outdoors after February 10 in Aransas County when soil has warmed and frost danger has passed.

With summer highs reaching 104°F in Aransas County, provide afternoon shade for Rosemary and water deeply in the morning.

With 67" of annual rainfall in Aransas 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 →

Frequently Asked Questions

When should I plant Rosemary in Aransas County, TX?

Aransas County is in Zone 9b with an average last frost of February 10. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Aransas County, TX?

Aransas County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 10 and first fall frost is December 12.

🌱

Your Aransas County Garden Planner — Free

A 24-page printable planner built for Aransas County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Aransas County, TX. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.