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When to Plant Arugula in Washington County, TX

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.

Washington County, Texas is in USDA Zone 8b. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.

At an elevation of 386 feet, Washington County receives approximately 58.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90ยฐF, providing good warmth for Arugula during the growing season. Clay soil retains moisture well for Arugula, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Arugula root diseases.

Washington County, TX (Zone 8b) Year-round
270 days
Last Spring Frost March 2
270 growing days
First Fall Frost November 27

Washington County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (175 days to spare)
Start indoors: Jan 11 Transplant: Feb 15 🍅 Harvest: Mar 22 – May 24
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Jan 26 Transplant: Mar 2 🍅 Harvest: Apr 6 – Jun 8
Safe Start (90%) ✓ Fits season (173 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: Apr 26 – Jun 28

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 Washington County

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

Soil pH

Your soil pH (6.9โ€“8.4) is more alkaline than Arugula prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Washington County is workable for Arugula. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Arugula.

How to Plant Arugula

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Arugula

11
successive plantings in your 270-day season

Sow every 3.4 weeks. Last sowing by Oct 08 to harvest before frost.

For a dedicated fall crop, sow by Sep 18.

Plant Water Budget

Plant needs
0.6″/week
Rainfall provides
0.9″/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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.9" 0" โ„๏ธ Dormant
Mar 2.6" 4.3" 0" โœ… Rainfall sufficient
Apr 2.6" 5.8" 0" โœ… Rainfall sufficient
May 2.6" 8.3" 0" โœ… Rainfall sufficient
Jun 2.6" 9.9" 0" โœ… Rainfall sufficient
Jul 2.6" 7" 0" โœ… Rainfall sufficient
Aug 2.6" 7.4" 0" โœ… Rainfall sufficient
Sep 2.6" 5.2" 0" โœ… Rainfall sufficient
Oct 2.6" 4.2" 0" โœ… Rainfall sufficient
Nov 2.6" 2" 0.6" ๐Ÿ’ง Light watering
Dec โ€” 1.4" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Washington County). Supplement amounts are based on average rainfall โ€” 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" 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.

Arugula needs ~700 GDD — county provides 4,725 GDD Excellent fit

Arugula Planting Timeline โ€” Washington County, TX

Arugula Planting Calendar

Activity When Date Range
Start Indoors January 26 Jan 26 โ€“ Feb 9
Transplant Outdoors March 2 Mar 2 โ€“ Mar 16
Direct Sow February 16 Feb 16 โ€“ Mar 9
Harvest April 6 Apr 6 โ€“ Jun 8
Fall Sowing September 18 Sep 18 โ€“ Oct 2

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

30โ€“50 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8b

๐Ÿ“† Growing Season

270 days in Washington County

Growing Tips for Arugula in Washington County

Direct sow Arugula outdoors after March 02 in Washington County when soil has warmed and frost danger has passed.

With Washington County's clay soil (37% clay), work in 3-4 inches of compost before planting Arugula. Avoid tilling when soil is wet to prevent compaction.

Your generous 270.0-day season in Washington 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 →

Frequently Asked Questions

When should I plant Arugula in Washington County, TX?

Washington County is in Zone 8b with an average last frost of March 2. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, TX?

Washington County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 2 and first fall frost is November 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 8b organize planting dates, track what's growing, and never miss a planting window.

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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 Washington County, TX. Local conditions may vary. Last updated: April 2026.