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When to Plant Watercress in Orleans Parish, LA

Orleans Parish, Louisiana Zone 9b May

May to-do list for Orleans Parish, Louisiana

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost February 20
Avg. first frost November 23
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Harvest watercress as they ripen

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

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Watercress is a semi-aquatic plant with a peppery, tangy flavor rich in vitamins and minerals. It grows naturally along streams and can be cultivated in containers with standing water.

Orleans Parish, Louisiana is in USDA Zone 9b. 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 489 feet, Orleans Parish receives approximately 50.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 101°F, so Watercress may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Watercress will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.

Orleans Parish, LA (Zone 9b) Year-round
276 days
Last Spring Frost February 20
276 growing days
First Fall Frost November 23
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Orleans Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (212 days to spare)
Start indoors: Jan 2 Transplant: Jan 30 🍅 Harvest: Mar 13 – Apr 17
Recommended (50%) ✓ Fits season (199 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Apr 3 – May 8
Safe Start (90%) ✓ Fits season (186 days to spare)
Start indoors: Mar 2 Transplant: Mar 30 🍅 Harvest: May 11 – Jun 15

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 Orleans Parish

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Watercress.

Organic Matter

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

How to Plant Watercress

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 Watercress

8
successive plantings in your 276-day season

Sow every 4.6 weeks. Last sowing by Sep 24 to harvest before frost.

For a dedicated fall crop, sow by Sep 28.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 859 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Watercress

Watercress needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Watercress Needs Rainfall You Supplement Action
Jan 4.2" 0" ❄️ Dormant
Feb 6.5" 4.2" 2.3" 💧 Light watering
Mar 6.5" 4.4" 2.1" 💧 Light watering
Apr 6.5" 3.9" 2.6" 💧 Light watering
May 6.5" 4.4" 2.1" 💧 Light watering
Jun 6.5" 4.9" 1.6" 💧 Light watering
Jul 6.5" 4.3" 2.2" 💧 Light watering
Aug 6.5" 5.1" 1.4" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 3.4" 3.1" 💧 Light watering
Nov 6.5" 3.8" 2.7" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

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

Watercress 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.

Watercress needs ~1,288 GDD — county provides 7,132 GDD Excellent fit

Watercress Planting Timeline — Orleans Parish, LA

Watercress 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 April 3 Apr 3 – May 8
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
April Harvest
May Harvest
June
July
August
September Fall Sowing
October Fall Sowing
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

276 days in Orleans Parish

Growing Tips for Watercress in Orleans Parish

Direct sow Watercress outdoors after February 20 in Orleans Parish when soil has warmed and frost danger has passed.

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

With summer highs reaching 101°F in Orleans Parish, provide afternoon shade for Watercress and water deeply in the morning.

Your generous 277.0-day season in Orleans Parish allows multiple plantings of Watercress. Sow every 20.0 days for continuous harvest.

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

General growing tips

Grow in containers with trays of water kept fresh. Provide partial shade and cool conditions. Harvest stems by cutting above water level. Replace water frequently to prevent stagnation.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Watercress in Orleans Parish, LA?

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

What planting zone is Orleans Parish, LA?

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

🌱

Your Orleans Parish Garden Planner — Free

A 24-page printable planner built for Orleans Parish (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 Orleans Parish, LA. Local conditions may vary. Last updated: May 2026.

Sources & credits

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