Blog

When to Plant Watercress in Forest County, PA

Forest County, Pennsylvania Zone 6a May

Top priorities for Forest County, Pennsylvania gardeners in May

May is a pivotal month for Forest County, Pennsylvania gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 13
Avg. first frost October 13
Soil temp (4") 59°F
Watering Moderate
Pest pressure Low
Daylight 14.3 hrs
  1. Harden off and plant watercress

    Your last frost (May 13) has passed. These warm-season crops can handle outdoor soil now.

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

Instant PDF download. No spam, unsubscribe any time.

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.

Forest County, Pennsylvania is in USDA Zone 6a. The average last spring frost is May 13 and the first fall frost is October 13, giving you a growing season of approximately 153 days.

At an elevation of 125 feet, Forest County receives approximately 40.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Watercress to ensure they mature before fall.

Forest County, PA (Zone 6a) Moderate season
153 days
Last Spring Frost May 13
153 growing days
First Fall Frost October 13

Forest County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (78 days to spare)
Start indoors: Mar 31 Transplant: May 5 🍅 Harvest: Jun 16 – Jul 21
Recommended (50%) ✓ Fits season (76 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: Jun 24 – Jul 29
Safe Start (90%) ✓ Fits season (71 days to spare)
Start indoors: Apr 27 Transplant: Jun 1 🍅 Harvest: Jul 13 – Aug 17

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 Forest County

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

Soil pH

Your soil pH (5.2–6.8) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). 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

4
successive plantings in your 153-day season

Sow every 4.6 weeks. Last sowing by Aug 14 to harvest before frost.

For a dedicated fall crop, sow by Aug 04.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.1″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 521 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 3.1" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 6.5" 3.6" 2.9" 💧 Light watering
Jun 6.5" 4.2" 2.3" 💧 Light watering
Jul 6.5" 3.7" 2.8" 💧 Light watering
Aug 6.5" 4" 2.5" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 2.7" 3.8" 🚿 Regular watering
Nov 3.4" 0" ❄️ Dormant
Dec 3.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Forest 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 ~612 GDD — county provides 1,874 GDD Excellent fit

Watercress Planting Timeline — Forest County, PA

Watercress Planting Calendar

Activity When Date Range
Start Indoors April 8 Apr 8 – Apr 22
Transplant Outdoors May 13 May 13 – May 27
Direct Sow April 29 Apr 29 – May 20
Harvest June 24 Jun 24 – Jul 29
Fall Sowing August 4 Aug 4 – Aug 18

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors 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 · 1-2 times/week

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6a

📆 Growing Season

153 days in Forest County

Growing Tips for Watercress in Forest County

Direct sow Watercress outdoors after May 13 in Forest County when soil has warmed and frost danger has passed.

Your generous 153.0-day season in Forest 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 Forest County, PA?

Forest County is in Zone 6a with an average last frost of May 13. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Forest County, PA?

Forest County, Pennsylvania is in USDA Hardiness Zone 6a. The average last spring frost is May 13 and first fall frost is October 13.

🌱

Your Forest County Garden Planner — Free

A 24-page printable planner built for Forest County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Forest County, PA. 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.