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When to Plant Rosemary in Brewster County, TX

Brewster County, Texas Zone 8b May

Top priorities for Brewster County, Texas gardeners in May

May is a pivotal month for Brewster County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 27
Avg. first frost November 11
Soil temp (4") 61°F
Watering Critical
Pest pressure Moderate
Daylight 13.5 hrs
June will be here before you know it — start on
  • First harvests: rosemary

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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.

Brewster County, Texas is in USDA Zone 8b. The average last spring frost is March 27 and the first fall frost is November 11, giving you a growing season of approximately 229 days.

At an elevation of 2,724 feet, Brewster County receives approximately 43.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 98°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.

Brewster County, TX (Zone 8b) Long season
229 days
Last Spring Frost March 27
229 growing days
First Fall Frost November 11

Brewster County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Mar 20 🍅 Harvest: Jun 12 – Oct 30
Recommended (50%) ✗ May not fit
Transplant: Apr 3 🍅 Harvest: Jun 26 – Nov 13
Safe Start (90%) ✓ Fits season (4 days to spare)
Transplant: Apr 22 🍅 Harvest: Jul 15 – Dec 2

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 Brewster County

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

Soil pH

Your soil pH (7.9–8.4) is more alkaline than Rosemary prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Brewster County warms quickly in spring but drains fast. Rosemary will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Rosemary.

How to Plant Rosemary

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

Succession Planting Rosemary

3
successive plantings in your 229-day season

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

Plant Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 3.2" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 1.3" 2.5" 0" ✅ Rainfall sufficient
Apr 1.3" 1.5" 0" ✅ Rainfall sufficient
May 1.3" 0.8" 0.5" 💧 Light watering
Jun 1.3" 1.2" 0.1" 💧 Light watering
Jul 1.3" 7.1" 0" ✅ Rainfall sufficient
Aug 1.3" 9.4" 0" ✅ Rainfall sufficient
Sep 1.3" 6.1" 0" ✅ Rainfall sufficient
Oct 1.3" 4" 0" ✅ Rainfall sufficient
Nov 1.3" 2.6" 0" ✅ Rainfall sufficient
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Brewster 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 ~3,055 GDD — county provides 5,381 GDD Excellent fit

Rosemary Planting Timeline — Brewster County, TX

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 3 Apr 3 – Apr 17
Harvest June 26 Jun 26 – Nov 13

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Transplant Outdoors
May
June Harvest
July Harvest
August Harvest
September Harvest
October Harvest
November Harvest
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: too_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

229 days in Brewster County

Growing Tips for Rosemary in Brewster County

Direct sow Rosemary outdoors after March 27 in Brewster County when soil has warmed and frost danger has passed.

Sandy soil in Brewster County dries quickly — mulch Rosemary with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 98°F in Brewster County, provide afternoon shade for Rosemary and water deeply in the morning.

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 Brewster County, TX?

Brewster County is in Zone 8b with an average last frost of March 27. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Brewster County, TX?

Brewster County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 27 and first fall frost is November 11.

🌱

Your Brewster County Garden Planner — Free

A 24-page printable planner built for Brewster County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Brewster 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.