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When to Plant Arugula in Mathis, TX

San Patricio County, Texas Zone 9b July

July to-do list for San Patricio County, Texas

July is a pivotal month for San Patricio County, Texas gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost February 12
Avg. first frost December 9
Soil temp (4") 91°F
Watering Low
Pest pressure High
Daylight 13.6 hrs

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Arugula is a fast-growing cool-season green with a peppery, nutty flavor. It is excellent in salads and can be harvested as baby greens or mature leaves.

Mathis, 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 Arugula may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Arugula root diseases.

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

Mathis Soil Profile

Soil Type

Loam

Soil pH

6.8-7.2

Drainage

Well Drained

Arugula Planting Risk Windows

Early Start (70% safe) ✓ Fits season (217 days to spare)
Start indoors: Dec 23 Transplant: Jan 20 🍅 Harvest: Feb 24 – Apr 28
Recommended (50%) ✓ Fits season (202 days to spare)
Start indoors: Jan 15 Transplant: Feb 12 🍅 Harvest: Mar 19 – May 21
Safe Start (90%) ✓ Fits season (189 days to spare)
Start indoors: Feb 10 Transplant: Mar 10 🍅 Harvest: Apr 14 – Jun 16

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 Mathis

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

Soil pH

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

Soil Texture

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

Organic Matter

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

How to Plant Arugula

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 Arugula

12
successive plantings in your 300-day season

Sow every 3.4 weeks. Last sowing by Oct 20 to harvest before frost.

For a dedicated fall crop, sow by Oct 14.

Arugula Water Budget

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

Monthly Watering Guide for Arugula

Arugula needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Arugula Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 2.6" 1.7" 0.9" 💧 Light watering
Mar 2.6" 3.8" 0" ✅ Rainfall sufficient
Apr 2.6" 6.4" 0" ✅ Rainfall sufficient
May 2.6" 8.5" 0" ✅ Rainfall sufficient
Jun 2.6" 8.1" 0" ✅ Rainfall sufficient
Jul 2.6" 7.5" 0" ✅ Rainfall sufficient
Aug 2.6" 5.6" 0" ✅ Rainfall sufficient
Sep 2.6" 5" 0" ✅ Rainfall sufficient
Oct 2.6" 3.1" 0" ✅ Rainfall sufficient
Nov 2.6" 2" 0.6" 💧 Light watering
Dec 2.6" 1.4" 1.2" 💧 Light 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.

Arugula 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.

Arugula needs ~1,000 GDD — county provides 7,525 GDD Excellent fit

Arugula Planting Timeline — Mathis, TX

Arugula 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 21
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

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

30–50 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 9b

📆 Growing Season

300 days in San Patricio County

Growing Tips for Arugula in Mathis

Direct sow Arugula 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 Arugula 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 Arugula. Sow every 15.0 days for continuous harvest.

Common pests for Arugula in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Sow seeds directly every 2-3 weeks for continuous harvest. Provide afternoon shade in warm weather to prevent bolting. Harvest outer leaves first to extend production.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

🌱

Your San Patricio County Garden Planner — Free

A 22-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: July 2026.