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When to Plant Rosemary in Austin 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.

Austin County, Texas is in USDA Zone 8b. The average last spring frost is February 28 and the first fall frost is November 29, giving you a growing season of approximately 274 days.

At an elevation of 350 feet, Austin County receives approximately 68.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90ยฐF, 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.

Austin County, TX (Zone 8b) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29

Austin County Soil Profile

Soil Type

Clay

Soil pH

6.8-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (44 days to spare)
Transplant: Feb 20 🍅 Harvest: May 15 – Oct 2
Recommended (50%) ✓ Fits season (43 days to spare)
Transplant: Mar 7 🍅 Harvest: May 30 – Oct 17
Safe Start (90%) ✓ Fits season (43 days to spare)
Transplant: Mar 29 🍅 Harvest: Jun 21 – Nov 8

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 Austin County

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

Soil pH

Your soil pH (6.8โ€“8.1) overlaps with Rosemary's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

Heavy clay soil (41% clay) in Austin County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.2%). 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 274-day season

Sow every 9.1 weeks. Last sowing by Jun 02 to harvest before frost.

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
1.1″/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€” 1.7" 0" โ„๏ธ Dormant
Feb 1.3" 2.4" 0" โœ… Rainfall sufficient
Mar 1.3" 4.3" 0" โœ… Rainfall sufficient
Apr 1.3" 7.2" 0" โœ… Rainfall sufficient
May 1.3" 9.6" 0" โœ… Rainfall sufficient
Jun 1.3" 11.9" 0" โœ… Rainfall sufficient
Jul 1.3" 8.5" 0" โœ… Rainfall sufficient
Aug 1.3" 9.2" 0" โœ… Rainfall sufficient
Sep 1.3" 5.7" 0" โœ… Rainfall sufficient
Oct 1.3" 4.6" 0" โœ… Rainfall sufficient
Nov 1.3" 2.2" 0" โœ… Rainfall sufficient
Dec โ€” 1.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Febโ€“Nov in Austin 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 ~2,275 GDD — county provides 4,812 GDD Excellent fit

Rosemary Planting Timeline โ€” Austin County, TX

Rosemary Planting Calendar

Activity When Date Range
Transplant Outdoors March 7 Mar 7 โ€“ Mar 21
Harvest May 30 May 30 โ€“ Oct 17

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Transplant Outdoors
April โ€”
May Harvest
June Harvest
July Harvest
August Harvest
September Harvest
October Harvest
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 8b

๐Ÿ“† Growing Season

274 days in Austin County

Growing Tips for Rosemary in Austin County

Direct sow Rosemary outdoors after February 28 in Austin County when soil has warmed and frost danger has passed.

With Austin County's clay soil (41% clay), work in 3-4 inches of compost before planting Rosemary. Avoid tilling when soil is wet to prevent compaction.

With 69" of annual rainfall in Austin County, ensure good drainage for Rosemary โ€” 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 Austin County, TX?

Austin County is in Zone 8b with an average last frost of February 28. Plan your Rosemary planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Austin County, TX?

Austin County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 28 and first fall frost is November 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Austin County gardeners in Zone 8b 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 Austin County, TX. Local conditions may vary. Last updated: April 2026.