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When to Plant Rosemary in Webb 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.

Webb County, Texas is in USDA Zone 9a. The average last spring frost is February 9 and the first fall frost is December 9, giving you a growing season of approximately 303 days.

At an elevation of 3,543 feet, Webb County receives approximately 50.9 inches of rainfall annually with predominantly loam soil. Summer highs average 95ยฐF, 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.

Webb County, TX (Zone 9a) Year-round
303 days
Last Spring Frost February 9
303 growing days
First Fall Frost December 9

Webb County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (86 days to spare)
Transplant: Jan 26 🍅 Harvest: Apr 20 – Sep 7
Recommended (50%) ✓ Fits season (72 days to spare)
Transplant: Feb 16 🍅 Harvest: May 11 – Sep 28
Safe Start (90%) ✓ Fits season (60 days to spare)
Transplant: Mar 12 🍅 Harvest: Jun 4 – Oct 22

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 Webb County

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

Soil pH

Your soil pH (6.6โ€“7.7) overlaps with Rosemary's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Webb County is excellent for Rosemary โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). 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 303-day season

Sow every 9.1 weeks. Last sowing by Jun 12 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 โ€” 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 โ€” 1.3" 0" โ„๏ธ Dormant
Feb 1.3" 1.9" 0" โœ… Rainfall sufficient
Mar 1.3" 2.8" 0" โœ… Rainfall sufficient
Apr 1.3" 5" 0" โœ… Rainfall sufficient
May 1.3" 8.3" 0" โœ… Rainfall sufficient
Jun 1.3" 7.6" 0" โœ… Rainfall sufficient
Jul 1.3" 5.9" 0" โœ… Rainfall sufficient
Aug 1.3" 6.4" 0" โœ… Rainfall sufficient
Sep 1.3" 5.2" 0" โœ… Rainfall sufficient
Oct 1.3" 3.4" 0" โœ… Rainfall sufficient
Nov 1.3" 1.7" 0" โœ… Rainfall sufficient
Dec 1.3" 1.5" 0" โœ… Rainfall sufficient

Water needs are for active growing months only (Febโ€“Dec in Webb County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~2,762 GDD — county provides 6,460 GDD Excellent fit

Rosemary Planting Timeline โ€” Webb County, TX

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors February 16 Feb 16 โ€“ Mar 2
Harvest May 11 May 11 โ€“ Sep 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Transplant Outdoors
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

80โ€“180 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

303 days in Webb County

Growing Tips for Rosemary in Webb County

Direct sow Rosemary outdoors after February 09 in Webb County when soil has warmed and frost danger has passed.

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 Webb County, TX?

Webb County is in Zone 9a with an average last frost of February 9. Plan your Rosemary planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Webb County, TX?

Webb County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 9 and first fall frost is December 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Webb County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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