Blog

When to Plant Arugula in St. Tammany Parish, LA

St. Tammany Parish, Louisiana Zone 9a May

St. Tammany Parish, Louisiana gardeners: here's your May plan

Here's what deserves your attention in St. Tammany Parish, Louisiana this month. Everything below is tailored to Zone 9a and timed around your local frost dates.

Avg. last frost February 20
Avg. first frost November 23
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest arugula as they ripen

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

Instant PDF download. No spam, unsubscribe any time.

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.

St. Tammany Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 20 and the first fall frost is November 23, giving you a growing season of approximately 276 days.

At an elevation of 321 feet, St. Tammany Parish receives approximately 57.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 96°F, so Arugula may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Arugula will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Arugula root diseases.

St. Tammany Parish, LA (Zone 9a) Year-round
276 days
Last Spring Frost February 20
276 growing days
First Fall Frost November 23

St. Tammany Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (191 days to spare)
Start indoors: Jan 2 Transplant: Jan 30 🍅 Harvest: Mar 6 – May 8
Recommended (50%) ✓ Fits season (178 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Mar 27 – May 29
Safe Start (90%) ✓ Fits season (165 days to spare)
Start indoors: Mar 2 Transplant: Mar 30 🍅 Harvest: May 4 – Jul 6

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 St. Tammany Parish

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

Soil pH

Your soil pH (4.8–6.1) is more acidic than Arugula prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in St. Tammany Parish warms quickly in spring but drains fast. Arugula will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Arugula.

Organic Matter

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

11
successive plantings in your 276-day season

Sow every 3.4 weeks. Last sowing by Oct 04 to harvest before frost.

For a dedicated fall crop, sow by Sep 28.

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 4.5" 0" ❄️ Dormant
Feb 2.6" 4.5" 0" ✅ Rainfall sufficient
Mar 2.6" 5.8" 0" ✅ Rainfall sufficient
Apr 2.6" 4.2" 0" ✅ Rainfall sufficient
May 2.6" 5.2" 0" ✅ Rainfall sufficient
Jun 2.6" 4.6" 0" ✅ Rainfall sufficient
Jul 2.6" 6.8" 0" ✅ Rainfall sufficient
Aug 2.6" 5.3" 0" ✅ Rainfall sufficient
Sep 2.6" 4.2" 0" ✅ Rainfall sufficient
Oct 2.6" 4.1" 0" ✅ Rainfall sufficient
Nov 2.6" 4.3" 0" ✅ Rainfall sufficient
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in St. Tammany Parish). 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 ~880 GDD — county provides 6,094 GDD Excellent fit

Arugula Planting Timeline — St. Tammany Parish, LA

Arugula Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors February 20 Feb 20 – Mar 6
Direct Sow January 30 Jan 30 – Feb 20
Harvest March 27 Mar 27 – May 29
Fall Sowing September 28 Sep 28 – Oct 12

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

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Start Indoors Transplant Outdoors Direct Sow
March Transplant Outdoors Harvest
April Harvest
May Harvest
June
July
August
September Fall Sowing
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: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

276 days in St. Tammany Parish

Growing Tips for Arugula in St. Tammany Parish

Direct sow Arugula outdoors after February 20 in St. Tammany Parish when soil has warmed and frost danger has passed.

Sandy soil in St. Tammany Parish dries quickly — mulch Arugula with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Summer highs in St. Tammany Parish reach 96°F — grow Arugula as a spring or fall crop. Use shade cloth if planting in summer.

Your generous 277.0-day season in St. Tammany Parish 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 St. Tammany Parish, LA?

St. Tammany Parish is in Zone 9a with an average last frost of February 20. Plan your Arugula planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Tammany Parish, LA?

St. Tammany Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 20 and first fall frost is November 23.

🌱

Your St. Tammany Parish Garden Planner — Free

A 24-page printable planner built for St. Tammany Parish (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for St. Tammany Parish, LA. 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.