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When to Plant Watercress in Jefferson Davis Parish, LA

Jefferson Davis Parish, Louisiana Zone 9a May

May in Jefferson Davis Parish, Louisiana — your action list

We've pulled the most time-sensitive tasks for Jefferson Davis Parish, Louisiana this May and put them front and centre. Tackle them in order.

Avg. last frost February 13
Avg. first frost December 7
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Pick watercress

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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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.

Jefferson Davis Parish, Louisiana is in USDA Zone 9a. The average last spring frost is February 13 and the first fall frost is December 7, giving you a growing season of approximately 297 days.

At an elevation of 381 feet, Jefferson Davis Parish receives approximately 61.2 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°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.

Jefferson Davis Parish, LA (Zone 9a) Year-round
297 days
Last Spring Frost February 13
297 growing days
First Fall Frost December 7
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Jefferson Davis Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (228 days to spare)
Start indoors: Jan 2 Transplant: Jan 30 🍅 Harvest: Mar 13 – Apr 17
Recommended (50%) ✓ Fits season (220 days to spare)
Start indoors: Jan 16 Transplant: Feb 13 🍅 Harvest: Mar 27 – May 1
Safe Start (90%) ✓ Fits season (215 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: Apr 17 – May 22

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 Jefferson Davis Parish

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

Soil pH

Your soil pH (5.2–6.3) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Jefferson Davis 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 (2.0%). 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

9
successive plantings in your 297-day season

Sow every 4.6 weeks. Last sowing by Oct 08 to harvest before frost.

For a dedicated fall crop, sow by Oct 12.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 497 gal / 100 sq ft

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 5.4" 0" ❄️ Dormant
Feb 6.5" 4.8" 1.7" 💧 Light watering
Mar 6.5" 5.7" 0.8" 💧 Light watering
Apr 6.5" 4.6" 1.9" 💧 Light watering
May 6.5" 5.3" 1.2" 💧 Light watering
Jun 6.5" 4.5" 2" 💧 Light watering
Jul 6.5" 6.7" 0" ✅ Rainfall sufficient
Aug 6.5" 6.2" 0.3" 💧 Light watering
Sep 6.5" 4.6" 1.9" 💧 Light watering
Oct 6.5" 3.7" 2.8" 💧 Light watering
Nov 6.5" 4.3" 2.2" 💧 Light watering
Dec 6.5" 5.4" 1.1" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Jefferson Davis 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 ~1,062 GDD — county provides 6,332 GDD Excellent fit

Watercress Planting Timeline — Jefferson Davis Parish, LA

Watercress Planting Calendar

Activity When Date Range
Start Indoors January 16 Jan 16 – Jan 30
Transplant Outdoors February 13 Feb 13 – Feb 27
Direct Sow January 23 Jan 23 – Feb 13
Harvest March 27 Mar 27 – May 1
Fall Sowing October 12 Oct 12 – Oct 26

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
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

297 days in Jefferson Davis Parish

Growing Tips for Watercress in Jefferson Davis Parish

Direct sow Watercress outdoors after February 13 in Jefferson Davis Parish when soil has warmed and frost danger has passed.

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

Your generous 298.0-day season in Jefferson Davis 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 Jefferson Davis Parish, LA?

Jefferson Davis Parish is in Zone 9a with an average last frost of February 13. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson Davis Parish, LA?

Jefferson Davis Parish, Louisiana is in USDA Hardiness Zone 9a. The average last spring frost is February 13 and first fall frost is December 7.

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Your Jefferson Davis Parish Garden Planner — Free

A 24-page printable planner built for Jefferson Davis 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.

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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 Jefferson Davis 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.