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When to Plant Watercress in Guernsey County, OH

Guernsey County, Ohio Zone 6b May

Guernsey County, Ohio gardeners: here's your May plan

Here's what deserves your attention in Guernsey County, Ohio this month. Everything below is tailored to Zone 6b and timed around your local frost dates.

Avg. last frost April 30
Avg. first frost October 16
Soil temp (4") 63°F
Watering Moderate
Pest pressure Low
Daylight 14.2 hrs
Coming up in June — start thinking about
  • Starting indoors: watercress
  • 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.

Guernsey County, Ohio is in USDA Zone 6b. The average last spring frost is April 30 and the first fall frost is October 16, giving you a growing season of approximately 169 days.

At an elevation of 790 feet, Guernsey County receives approximately 30.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Watercress during the growing season.

Guernsey County, OH (Zone 6b) Moderate season
169 days
Last Spring Frost April 30
169 growing days
First Fall Frost October 16

Guernsey County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (88 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 8 – Jul 13
Recommended (50%) ✓ Fits season (92 days to spare)
Start indoors: Mar 26 Transplant: Apr 30 🍅 Harvest: Jun 11 – Jul 16
Safe Start (90%) ✓ Fits season (86 days to spare)
Start indoors: Apr 12 Transplant: May 17 🍅 Harvest: Jun 28 – Aug 2

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 Guernsey County

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

Soil pH

Your soil pH (6.0–7.0) overlaps with Watercress's range (6.5–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.0%) — 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

5
successive plantings in your 169-day season

Sow every 4.6 weeks. Last sowing by Aug 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 1,127 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 1.2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 6.5" 2.8" 3.7" 🚿 Regular watering
May 6.5" 3.4" 3.1" 💧 Light watering
Jun 6.5" 4.1" 2.4" 💧 Light watering
Jul 6.5" 3.6" 2.9" 💧 Light watering
Aug 6.5" 3.1" 3.4" 🚿 Regular watering
Sep 6.5" 2.5" 4" 🚿 Regular watering
Oct 6.5" 2.4" 4.1" 🚿 Regular watering
Nov 2.2" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Guernsey 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 ~912 GDD — county provides 3,084 GDD Excellent fit

Watercress Planting Timeline — Guernsey County, OH

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 16 Apr 16 – May 7
Harvest June 11 Jun 11 – Jul 16
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing
September
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: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

169 days in Guernsey County

Growing Tips for Watercress in Guernsey County

Direct sow Watercress outdoors after April 30 in Guernsey County when soil has warmed and frost danger has passed.

Your generous 169.0-day season in Guernsey 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 Guernsey County, OH?

Guernsey County is in Zone 6b with an average last frost of April 30. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Guernsey County, OH?

Guernsey County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 30 and first fall frost is October 16.

🌱

Your Guernsey County Garden Planner — Free

A 24-page printable planner built for Guernsey 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 Guernsey County, OH. 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.