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When to Plant Watercress in Ulster County, NY

Ulster County, New York Zone 6a May

Top priorities for Ulster County, New York gardeners in May

A quick May briefing for Ulster County, New York gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 24
Avg. first frost October 23
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Get watercress seeds going inside

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

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.

Ulster County, New York is in USDA Zone 6a. The average last spring frost is April 24 and the first fall frost is October 23, giving you a growing season of approximately 182 days.

At an elevation of 1,121 feet, Ulster County receives approximately 39.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Watercress during the growing season.

Ulster County, NY (Zone 6a) Moderate season
182 days
Last Spring Frost April 24
182 growing days
First Fall Frost October 23
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Ulster County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (106 days to spare)
Start indoors: Mar 12 Transplant: Apr 16 🍅 Harvest: May 28 – Jul 2
Recommended (50%) ✓ Fits season (105 days to spare)
Start indoors: Mar 20 Transplant: Apr 24 🍅 Harvest: Jun 5 – Jul 10
Safe Start (90%) ✓ Fits season (100 days to spare)
Start indoors: Apr 9 Transplant: May 14 🍅 Harvest: Jun 25 – Jul 30

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 Ulster County

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

Soil pH

Your soil pH (4.8–6.8) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.7%). 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

5
successive plantings in your 182-day season

Sow every 4.6 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Aug 14.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 961 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 2.4" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3.2" 0" ❄️ Dormant
Apr 6.5" 2.9" 3.6" 🚿 Regular watering
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 3.7" 2.8" 💧 Light watering
Jul 6.5" 4.4" 2.1" 💧 Light watering
Aug 6.5" 3.9" 2.6" 💧 Light watering
Sep 6.5" 3.5" 3" 💧 Light watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 2.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Ulster 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 3,048 GDD Excellent fit

Watercress Planting Timeline — Ulster County, NY

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors April 24 Apr 24 – May 8
Direct Sow April 10 Apr 10 – May 1
Harvest June 5 Jun 5 – Jul 10
Fall Sowing August 14 Aug 14 – Aug 28

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
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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

182 days in Ulster County

Growing Tips for Watercress in Ulster County

Direct sow Watercress outdoors after April 24 in Ulster County when soil has warmed and frost danger has passed.

Your generous 182.0-day season in Ulster 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 Ulster County, NY?

Ulster County is in Zone 6a with an average last frost of April 24. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ulster County, NY?

Ulster County, New York is in USDA Hardiness Zone 6a. The average last spring frost is April 24 and first fall frost is October 23.

🌱

Your Ulster County Garden Planner — Free

A 24-page printable planner built for Ulster 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.

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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 Ulster County, NY. 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.