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When to Plant Lettuce in San Patricio County, TX

San Patricio County, Texas Zone 9b May

May in San Patricio County, Texas — your action list

Each item below is timed to San Patricio County, Texas's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 12
Avg. first frost December 9
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Basket week: lettuce

    If you can't use it all right away, check the food-preservation section of your planner.

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Lettuce is a fast-growing cool-season green available in leaf, romaine, butterhead, and crisphead types. It is the foundation of salads and one of the easiest crops to grow.

San Patricio County, Texas is in USDA Zone 9b. The average last spring frost is February 12 and the first fall frost is December 9, giving you a growing season of approximately 300 days.

At an elevation of 2,449 feet, San Patricio County receives approximately 54.7 inches of rainfall annually with predominantly loam soil. Summer highs average 100°F, so Lettuce may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Lettuce root diseases.

San Patricio County, TX (Zone 9b) Year-round
300 days
Last Spring Frost February 12
300 growing days
First Fall Frost December 9

San Patricio County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (210 days to spare)
Start indoors: Dec 23 Transplant: Jan 20 🍅 Harvest: Feb 24 – May 5
Recommended (50%) ✓ Fits season (195 days to spare)
Start indoors: Jan 15 Transplant: Feb 12 🍅 Harvest: Mar 19 – May 28
Safe Start (90%) ✓ Fits season (182 days to spare)
Start indoors: Feb 10 Transplant: Mar 10 🍅 Harvest: Apr 14 – Jun 23

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 San Patricio County

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

Soil pH

Your soil pH (6.8–7.2) overlaps with Lettuce's range (6.0–7.0), though not a perfect match.

Soil Texture

The loam soil in San Patricio County is excellent for Lettuce — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Lettuce.

How to Plant Lettuce

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Lettuce

12
successive plantings in your 300-day season

Sow every 3.4 weeks. Last sowing by Oct 10 to harvest before frost.

For a dedicated fall crop, sow by Oct 14.

Plant Water Budget

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

Monthly Watering Guide for Lettuce

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

Month Lettuce Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 3" 1.7" 1.3" 💧 Light watering
Mar 3" 3.8" 0" ✅ Rainfall sufficient
Apr 3" 6.4" 0" ✅ Rainfall sufficient
May 3" 8.5" 0" ✅ Rainfall sufficient
Jun 3" 8.1" 0" ✅ Rainfall sufficient
Jul 3" 7.5" 0" ✅ Rainfall sufficient
Aug 3" 5.6" 0" ✅ Rainfall sufficient
Sep 3" 5" 0" ✅ Rainfall sufficient
Oct 3" 3.1" 0" ✅ Rainfall sufficient
Nov 3" 2" 1" 💧 Light watering
Dec 3" 1.4" 1.6" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in San Patricio County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Lettuce 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.

Lettuce needs ~1,125 GDD — county provides 7,525 GDD Excellent fit

Lettuce Planting Timeline — San Patricio County, TX

Lettuce Planting Calendar

Activity When Date Range
Start Indoors January 15 Jan 15 – Jan 29
Transplant Outdoors February 12 Feb 12 – Feb 26
Direct Sow January 22 Jan 22 – Feb 12
Harvest March 19 Mar 19 – May 28
Fall Sowing October 14 Oct 14 – Oct 28

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March Harvest
April Harvest
May Harvest
June
July
August
September
October Fall Sowing
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

30–60 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

300 days in San Patricio County

Growing Tips for Lettuce in San Patricio County

Direct sow Lettuce outdoors after February 12 in San Patricio County when soil has warmed and frost danger has passed.

Summer highs in San Patricio County reach 100°F — grow Lettuce as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 301.0-day season in San Patricio County allows multiple plantings of Lettuce. Sow every 15.0 days for continuous harvest.

Common pests for Lettuce in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly every 2 weeks for continuous harvest. Provide afternoon shade in warm weather to delay bolting. Harvest in the morning for crispest leaves.

Recommended Lettuce Varieties for San Patricio County

Bolt-resistant varieties for warm summers — grow as spring/fall crop

Jericho Muir Nevada New Red Fire

Companion Planting

Good Companions

Avoid Planting Near

  • Celery

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Lettuce Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let plants bolt and flower. Harvest seed heads when fluffy.
Storage Store airtight; viable 6 years at 35°F, under 45% humidity.

Very easy to save. Let a few plants bolt each season.

Frequently Asked Questions

When should I plant Lettuce in San Patricio County, TX?

San Patricio County is in Zone 9b with an average last frost of February 12. Plan your Lettuce planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Patricio County, TX?

San Patricio County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 12 and first fall frost is December 9.

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A 24-page printable planner built for San Patricio County (Zone 9b). 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 San Patricio 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.