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When to Plant Rosemary in Erath County, TX

Erath County, Texas Zone 8b May

May in Erath County, Texas — your action list

Welcome to May in Zone 8b. These are the moves that will have the biggest impact on your growing season.

Avg. last frost March 25
Avg. first frost November 11
Soil temp (4") 64°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
Get ahead of June
  • 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.

Erath County, Texas is in USDA Zone 8b. The average last spring frost is March 25 and the first fall frost is November 11, giving you a growing season of approximately 231 days.

At an elevation of 1,968 feet, Erath County receives approximately 55.9 inches of rainfall annually with predominantly clay soil. Summer highs average 92°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.

Erath County, TX (Zone 8b) Long season
231 days
Last Spring Frost March 25
231 growing days
First Fall Frost November 11

Erath County Soil Profile

Soil Type

Clay

Soil pH

7.3-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (2 days to spare)
Transplant: Mar 23 🍅 Harvest: Jun 15 – Nov 2
Recommended (50%) ✓ Fits season (0 days to spare)
Transplant: Apr 1 🍅 Harvest: Jun 24 – Nov 11
Safe Start (90%) ✗ May not fit
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 Erath County

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

Soil pH

Your soil pH (7.3–7.7) overlaps with Rosemary's range (6.0–7.5), though not a perfect match.

Soil Texture

Heavy clay soil (46% clay) in Erath County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). Annual compost additions will help Rosemary.

How to Plant Rosemary

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

Succession Planting Rosemary

3
successive plantings in your 231-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
1.0″/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 1.6" 0" ❄️ Dormant
Feb 2.1" 0" ❄️ Dormant
Mar 1.3" 3.2" 0" ✅ Rainfall sufficient
Apr 1.3" 5.8" 0" ✅ Rainfall sufficient
May 1.3" 7.2" 0" ✅ Rainfall sufficient
Jun 1.3" 8.1" 0" ✅ Rainfall sufficient
Jul 1.3" 8.1" 0" ✅ Rainfall sufficient
Aug 1.3" 6.7" 0" ✅ Rainfall sufficient
Sep 1.3" 5.9" 0" ✅ Rainfall sufficient
Oct 1.3" 4" 0" ✅ Rainfall sufficient
Nov 1.3" 2" 0" ✅ Rainfall sufficient
Dec 1.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Erath 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 ~2,470 GDD — county provides 4,389 GDD Excellent fit

Rosemary Planting Timeline — Erath County, TX

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors April 1 Apr 1 – Apr 15
Harvest June 24 Jun 24 – Nov 11

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: acceptable

🗺️ USDA Zone

Zone 8b

📆 Growing Season

231 days in Erath County

Growing Tips for Rosemary in Erath County

Direct sow Rosemary outdoors after March 25 in Erath County when soil has warmed and frost danger has passed.

With Erath County's clay soil (46% clay), work in 3-4 inches of compost before planting Rosemary. Avoid tilling when soil is wet to prevent compaction.

With 56" of annual rainfall in Erath 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 Erath County, TX?

Erath County is in Zone 8b with an average last frost of March 25. Plan your Rosemary planting based on this frost date — see the calendar above for exact timing.

What planting zone is Erath County, TX?

Erath County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 25 and first fall frost is November 11.

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Your Erath County Garden Planner — Free

A 24-page printable planner built for Erath 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 Erath 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.