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When to Plant Mint in Starr County, TX

Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.

Starr County, Texas is in USDA Zone 9b. The average last spring frost is February 3 and the first fall frost is December 16, giving you a growing season of approximately 316 days.

At an elevation of 2,451 feet, Starr County receives approximately 55.4 inches of rainfall annually with predominantly loam soil. Summer highs average 98ยฐF, so Mint may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mint root diseases.

Starr County, TX (Zone 9b) Year-round
316 days
Last Spring Frost February 3
316 growing days
First Fall Frost December 16

Starr County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (186 days to spare)
Transplant: Jan 25 🍅 Harvest: Mar 29 – Jun 7
Recommended (50%) ✓ Fits season (176 days to spare)
Transplant: Feb 10 🍅 Harvest: Apr 14 – Jun 23
Safe Start (90%) ✓ Fits season (157 days to spare)
Transplant: Mar 10 🍅 Harvest: May 12 – Jul 21

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 Starr County

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

Soil pH

Your soil pH (6.8โ€“7.5) is more alkaline than Mint prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Mint.

How to Plant Mint

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

Succession Planting Mint

6
successive plantings in your 316-day season

Sow every 6.9 weeks. Last sowing by Sep 17 to harvest before frost.

Plant Water Budget

Plant needs
0.7″/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 Mint

Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb 3" 1.9" 1.1" ๐Ÿ’ง Light watering
Mar 3" 3.4" 0" โœ… Rainfall sufficient
Apr 3" 6.6" 0" โœ… Rainfall sufficient
May 3" 8.8" 0" โœ… Rainfall sufficient
Jun 3" 7.6" 0" โœ… Rainfall sufficient
Jul 3" 7" 0" โœ… Rainfall sufficient
Aug 3" 6.4" 0" โœ… Rainfall sufficient
Sep 3" 4.9" 0" โœ… Rainfall sufficient
Oct 3" 4" 0" โœ… Rainfall sufficient
Nov 3" 1.6" 1.4" ๐Ÿ’ง Light watering
Dec 3" 1.6" 1.4" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Starr County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Mint 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.

Mint needs ~1,762 GDD — county provides 7,449 GDD Excellent fit

Mint Planting Timeline โ€” Starr County, TX

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors February 10 Feb 10 โ€“ Feb 24
Harvest April 14 Apr 14 โ€“ Jun 23

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

316 days in Starr County

Growing Tips for Mint in Starr County

Direct sow Mint outdoors after February 03 in Starr County when soil has warmed and frost danger has passed.

With summer highs reaching 98ยฐF in Starr County, provide afternoon shade for Mint and water deeply in the morning.

General growing tips

Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.

Companion Planting

Good Companions

Avoid Planting Near

  • Parsley

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mint in Starr County, TX?

Starr County is in Zone 9b with an average last frost of February 3. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Starr County, TX?

Starr County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 3 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Starr County gardeners in Zone 9b 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 Starr County, TX. Local conditions may vary. Last updated: April 2026.