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When to Plant Arugula in Caldwell 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.

Caldwell County, Texas is in USDA Zone 8b. The average last spring frost is February 27 and the first fall frost is December 1, giving you a growing season of approximately 277 days.

At an elevation of 3,482 feet, Caldwell County receives approximately 60.8 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.

Caldwell County, TX (Zone 8b) Year-round
277 days
Last Spring Frost February 27
277 growing days
First Fall Frost December 1

Caldwell 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 (181 days to spare)
Start indoors: Jan 9 Transplant: Feb 13 🍅 Harvest: Mar 20 – May 22
Recommended (50%) ✓ Fits season (179 days to spare)
Start indoors: Jan 23 Transplant: Feb 27 🍅 Harvest: Apr 3 – Jun 5
Safe Start (90%) ✓ Fits season (168 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 Caldwell County

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

Soil pH

Your soil pH (6.8โ€“8.1) is more alkaline than Arugula prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Heavy clay soil (43% clay) in Caldwell County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.

Organic Matter

Organic matter is moderate (3.3%). 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 277-day season

Sow every 3.4 weeks. Last sowing by Oct 12 to harvest before frost.

For a dedicated fall crop, sow by Sep 22.

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
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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€” 1.4" 0" โ„๏ธ Dormant
Feb 2.6" 2.1" 0.5" ๐Ÿ’ง Light watering
Mar 2.6" 4.1" 0" โœ… Rainfall sufficient
Apr 2.6" 6" 0" โœ… Rainfall sufficient
May 2.6" 9.9" 0" โœ… Rainfall sufficient
Jun 2.6" 9.2" 0" โœ… Rainfall sufficient
Jul 2.6" 7.5" 0" โœ… Rainfall sufficient
Aug 2.6" 7.9" 0" โœ… Rainfall sufficient
Sep 2.6" 5.6" 0" โœ… Rainfall sufficient
Oct 2.6" 3.8" 0" โœ… Rainfall sufficient
Nov 2.6" 1.8" 0.8" ๐Ÿ’ง Light watering
Dec 2.6" 1.5" 1.1" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Febโ€“Dec in Caldwell 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 4,865 GDD Excellent fit

Arugula Planting Timeline โ€” Caldwell County, TX

Arugula Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 โ€“ Feb 6
Transplant Outdoors February 27 Feb 27 โ€“ Mar 13
Direct Sow February 13 Feb 13 โ€“ Mar 6
Harvest April 3 Apr 3 โ€“ Jun 5
Fall Sowing September 22 Sep 22 โ€“ Oct 6

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Start Indoors Transplant Outdoors 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

277 days in Caldwell County

Growing Tips for Arugula in Caldwell County

Direct sow Arugula outdoors after February 27 in Caldwell County when soil has warmed and frost danger has passed.

With Caldwell County's clay soil (43% clay), work in 3-4 inches of compost before planting Arugula. Avoid tilling when soil is wet to prevent compaction.

Your generous 278.0-day season in Caldwell 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 Caldwell County, TX?

Caldwell County is in Zone 8b with an average last frost of February 27. Plan your Arugula planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Caldwell County, TX?

Caldwell County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is February 27 and first fall frost is December 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Caldwell 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 Caldwell County, TX. Local conditions may vary. Last updated: April 2026.