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When to Plant Watercress in Bristol County, MA

Bristol County, Massachusetts Zone 7a May

May to-do list for Bristol County, Massachusetts

Your Bristol County, Massachusetts garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 26
Avg. first frost October 17
Soil temp (4") 61°F
Watering Low
Pest pressure Low
Daylight 14.4 hrs
  1. Start watercress indoors

    These need a head start before your last frost (April 26). Sow into cells now so you're ready to transplant in a few weeks.

To set up a strong June, finish these tasks
  • 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.

Bristol County, Massachusetts is in USDA Zone 7a. The average last spring frost is April 26 and the first fall frost is October 17, giving you a growing season of approximately 174 days.

At an elevation of 833 feet, Bristol County receives approximately 47.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Watercress during the growing season.

Bristol County, MA (Zone 7a) Moderate season
174 days
Last Spring Frost April 26
174 growing days
First Fall Frost October 17

Bristol County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (98 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 31 – Jul 5
Recommended (50%) ✓ Fits season (97 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: Jun 7 – Jul 12
Safe Start (90%) ✓ Fits season (94 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 Bristol County

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

Soil pH

Your soil pH (5.1–6.7) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bristol 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 174-day season

Sow every 4.6 weeks. Last sowing by Aug 18 to harvest before frost.

For a dedicated fall crop, sow by Aug 08.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.2″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 547 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 3.8" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 6.5" 4.4" 2.1" 💧 Light watering
May 6.5" 4" 2.5" 💧 Light watering
Jun 6.5" 4.4" 2.1" 💧 Light watering
Jul 6.5" 4.3" 2.2" 💧 Light watering
Aug 6.5" 4.3" 2.2" 💧 Light watering
Sep 6.5" 4.2" 2.3" 💧 Light watering
Oct 6.5" 4.2" 2.3" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Bristol 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 2,914 GDD Excellent fit

Watercress Planting Timeline — Bristol County, MA

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 22 Mar 22 – Apr 5
Transplant Outdoors April 26 Apr 26 – May 10
Direct Sow April 12 Apr 12 – May 3
Harvest June 7 Jun 7 – Jul 12
Fall Sowing August 8 Aug 8 – Aug 22

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 · 1-2 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

174 days in Bristol County

Growing Tips for Watercress in Bristol County

Direct sow Watercress outdoors after April 26 in Bristol County when soil has warmed and frost danger has passed.

Your generous 174.0-day season in Bristol 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 Bristol County, MA?

Bristol County is in Zone 7a with an average last frost of April 26. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bristol County, MA?

Bristol County, Massachusetts is in USDA Hardiness Zone 7a. The average last spring frost is April 26 and first fall frost is October 17.

🌱

Your Bristol County Garden Planner — Free

A 24-page printable planner built for Bristol 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.

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 Bristol County, MA. 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.