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When to Plant Watercress in Wayne County, IL

Wayne County, Illinois Zone 6b May

Wayne County, Illinois gardeners: here's your May plan

Each item below is timed to Wayne County, Illinois's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 8
Avg. first frost October 27
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Time to start watercress inside

    You're about 25 weeks out from your last frost — the perfect window to get these germinating indoors.

  2. Bring in the watercress

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

Coming up in June — start thinking about
  • 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.

Wayne County, Illinois is in USDA Zone 6b. The average last spring frost is April 8 and the first fall frost is October 27, giving you a growing season of approximately 202 days.

At an elevation of 924 feet, Wayne County receives approximately 35.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85°F, providing good warmth for Watercress during the growing season.

Wayne County, IL (Zone 6b) Long season
202 days
Last Spring Frost April 8
202 growing days
First Fall Frost October 27

Wayne County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: May 14 – Jun 18
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: May 20 – Jun 24
Safe Start (90%) ✓ Fits season (131 days to spare)
Start indoors: Mar 16 Transplant: Apr 20 🍅 Harvest: Jun 1 – 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 Wayne County

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

Soil pH

Your soil pH (5.8–6.9) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.9%) — Watercress will thrive.

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 202-day season

Sow every 4.6 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 18.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.7″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,635 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 1.3" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 6.5" 3.3" 3.2" 💧 Light watering
May 6.5" 4.3" 2.2" 💧 Light watering
Jun 6.5" 4.6" 1.9" 💧 Light watering
Jul 6.5" 4.4" 2.1" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3.1" 3.4" 🚿 Regular watering
Oct 6.5" 3" 3.5" 🚿 Regular watering
Nov 2.1" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Wayne 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 ~688 GDD — county provides 2,777 GDD Excellent fit

Watercress Planting Timeline — Wayne County, IL

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 4 Mar 4 – Mar 18
Transplant Outdoors April 8 Apr 8 – Apr 22
Direct Sow March 25 Mar 25 – Apr 15
Harvest May 20 May 20 – Jun 24
Fall Sowing August 18 Aug 18 – Sep 1

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

Month-by-Month Timeline

MonthActivities
January
February
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 6b

📆 Growing Season

202 days in Wayne County

Growing Tips for Watercress in Wayne County

Direct sow Watercress outdoors after April 08 in Wayne County when soil has warmed and frost danger has passed.

Your generous 202.0-day season in Wayne 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 Wayne County, IL?

Wayne County is in Zone 6b with an average last frost of April 8. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wayne County, IL?

Wayne County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 8 and first fall frost is October 27.

🌱

Your Wayne County Garden Planner — Free

A 24-page printable planner built for Wayne County (Zone 6b). 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 Wayne County, IL. 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.