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When to Plant Watercress in Marshall County, MS

Marshall County, Mississippi Zone 7b May

May in Marshall County, Mississippi — your action list

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 March 27
Avg. first frost October 31
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Time to start watercress inside

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

  2. Start harvesting watercress

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

A few tasks this May that'll pay off in June
  • First harvests: watercress

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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.

Marshall County, Mississippi is in USDA Zone 7b. The average last spring frost is March 27 and the first fall frost is October 31, giving you a growing season of approximately 218 days.

At an elevation of 255 feet, Marshall County receives approximately 52.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 93°F, providing good warmth for Watercress during the growing season. Clay soil retains moisture well for Watercress, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.

Marshall County, MS (Zone 7b) Long season
218 days
Last Spring Frost March 27
218 growing days
First Fall Frost October 31

Marshall County Soil Profile

Soil Type

Clay Loam

Soil pH

5.6-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Feb 13 Transplant: Mar 20 🍅 Harvest: May 1 – Jun 5
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 8 – Jun 12
Safe Start (90%) ✓ Fits season (145 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 27 – Jul 1

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 Marshall County

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

Soil pH

Your soil pH (5.6–6.3) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

The clay loam soil in Marshall County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Watercress.

How to Plant Watercress

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 Watercress

6
successive plantings in your 218-day season

Sow every 4.6 weeks. Last sowing by Sep 01 to harvest before frost.

For a dedicated fall crop, sow by Aug 22.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 963 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 4.5" 0" ❄️ Dormant
Feb 4.7" 0" ❄️ Dormant
Mar 6.5" 4.9" 1.6" 💧 Light watering
Apr 6.5" 3.7" 2.8" 💧 Light watering
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 5.1" 1.4" 💧 Light watering
Aug 6.5" 5.6" 0.9" 💧 Light watering
Sep 6.5" 4.4" 2.1" 💧 Light watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 3.9" 0" ❄️ Dormant
Dec 4.2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Oct in Marshall County). 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 ~988 GDD — county provides 4,305 GDD Excellent fit

Watercress Planting Timeline — Marshall County, MS

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 13 Mar 13 – Apr 3
Harvest May 8 May 8 – Jun 12
Fall Sowing August 22 Aug 22 – Sep 5

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

Month-by-Month Timeline

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

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 7b

📆 Growing Season

218 days in Marshall County

Growing Tips for Watercress in Marshall County

Direct sow Watercress outdoors after March 27 in Marshall County when soil has warmed and frost danger has passed.

With Marshall County's clay soil (34% clay), work in 3-4 inches of compost before planting Watercress. Avoid tilling when soil is wet to prevent compaction.

Your generous 218.0-day season in Marshall County 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 Marshall County, MS?

Marshall County is in Zone 7b with an average last frost of March 27. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, MS?

Marshall County, Mississippi is in USDA Hardiness Zone 7b. The average last spring frost is March 27 and first fall frost is October 31.

🌱

Your Marshall County Garden Planner — Free

A 24-page printable planner built for Marshall County (Zone 7b). 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 Marshall County, MS. 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.