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When to Plant Watercress in Marshall County, KY

Marshall County, Kentucky Zone 7a May

Your May planting checklist for Marshall County, Kentucky

We've pulled the most time-sensitive tasks for Marshall County, Kentucky this May and put them front and centre. Tackle them in order.

Avg. last frost April 3
Avg. first frost November 1
Soil temp (4") 61°F
Watering Moderate
Pest pressure Low
Daylight 14 hrs
  1. Time to start watercress inside

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Basket week: watercress

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Looking ahead to 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, Kentucky is in USDA Zone 7a. The average last spring frost is April 3 and the first fall frost is November 1, giving you a growing season of approximately 212 days.

At an elevation of 1,550 feet, Marshall County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Watercress during the growing season.

Marshall County, KY (Zone 7a) Long season
212 days
Last Spring Frost April 3
212 growing days
First Fall Frost November 1

Marshall County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (139 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 6 – Jun 10
Recommended (50%) ✓ Fits season (135 days to spare)
Start indoors: Feb 27 Transplant: Apr 3 🍅 Harvest: May 15 – Jun 19
Safe Start (90%) ✓ Fits season (135 days to spare)
Start indoors: Mar 14 Transplant: Apr 18 🍅 Harvest: May 30 – Jul 4

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 (5.5–7.1) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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 212-day season

Sow every 4.6 weeks. Last sowing by Sep 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,481 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 3.6" 0" ❄️ Dormant
Feb 4" 0" ❄️ Dormant
Mar 4" 0" ❄️ Dormant
Apr 6.5" 2.9" 3.6" 🚿 Regular watering
May 6.5" 3.2" 3.3" 🚿 Regular watering
Jun 6.5" 3.6" 2.9" 💧 Light watering
Jul 6.5" 5" 1.5" 💧 Light watering
Aug 6.5" 4" 2.5" 💧 Light watering
Sep 6.5" 3.5" 3" 💧 Light watering
Oct 6.5" 2.8" 3.7" 🚿 Regular watering
Nov 6.5" 3" 3.5" 🚿 Regular watering
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov 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 ~838 GDD — county provides 3,551 GDD Excellent fit

Watercress Planting Timeline — Marshall County, KY

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Harvest May 15 May 15 – Jun 19
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors 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 · 2-3 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

212 days in Marshall County

Growing Tips for Watercress in Marshall County

Direct sow Watercress outdoors after April 03 in Marshall County when soil has warmed and frost danger has passed.

Your generous 212.0-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, KY?

Marshall County is in Zone 7a with an average last frost of April 3. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Marshall County, KY?

Marshall County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 3 and first fall frost is November 1.

🌱

Your Marshall County Garden Planner — Free

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