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When to Plant Watercress in Vanderburgh County, IN

Vanderburgh County, Indiana Zone 7a May

What to do in May

Your garden in Vanderburgh County, Indiana is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 7
Avg. first frost October 29
Soil temp (4") 64°F
Watering Low
Pest pressure Low
Daylight 14.1 hrs
  1. Get watercress seeds going inside

    These need a head start before your last frost (April 7). Sow into cells now so you're ready to transplant in a few weeks.

  2. It's harvest week for watercress

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

June will be here before you know it — start on
  • 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.

Vanderburgh County, Indiana is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 29, giving you a growing season of approximately 205 days.

At an elevation of 901 feet, Vanderburgh County receives approximately 40.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Watercress during the growing season.

Vanderburgh County, IN (Zone 7a) Long season
205 days
Last Spring Frost April 7
205 growing days
First Fall Frost October 29
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Vanderburgh County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (129 days to spare)
Start indoors: Feb 24 Transplant: Mar 31 🍅 Harvest: May 12 – Jun 16
Recommended (50%) ✓ Fits season (128 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: May 19 – Jun 23
Safe Start (90%) ✓ Fits season (133 days to spare)
Start indoors: Mar 17 Transplant: Apr 21 🍅 Harvest: Jun 2 – Jul 7

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 Vanderburgh County

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

Soil pH

Your soil pH (6.0–6.8) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Vanderburgh 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

6
successive plantings in your 205-day season

Sow every 4.6 weeks. Last sowing by Aug 30 to harvest before frost.

For a dedicated fall crop, sow by Aug 20.

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 1,476 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 1.7" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 6.5" 4.2" 2.3" 💧 Light watering
May 6.5" 5" 1.5" 💧 Light watering
Jun 6.5" 5.1" 1.4" 💧 Light watering
Jul 6.5" 3.9" 2.6" 💧 Light watering
Aug 6.5" 3.8" 2.7" 💧 Light watering
Sep 6.5" 3.5" 3" 💧 Light watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 3.2" 0" ❄️ Dormant
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Vanderburgh 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 ~762 GDD — county provides 3,126 GDD Excellent fit

Watercress Planting Timeline — Vanderburgh County, IN

Watercress Planting Calendar

Activity When Date Range
Start Indoors March 3 Mar 3 – Mar 17
Transplant Outdoors April 7 Apr 7 – Apr 21
Direct Sow March 24 Mar 24 – Apr 14
Harvest May 19 May 19 – Jun 23
Fall Sowing August 20 Aug 20 – Sep 3

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
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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 7a

📆 Growing Season

205 days in Vanderburgh County

Growing Tips for Watercress in Vanderburgh County

Direct sow Watercress outdoors after April 07 in Vanderburgh County when soil has warmed and frost danger has passed.

Your generous 205.0-day season in Vanderburgh 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 Vanderburgh County, IN?

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

What planting zone is Vanderburgh County, IN?

Vanderburgh County, Indiana is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 29.

🌱

Your Vanderburgh County Garden Planner — Free

A 24-page printable planner built for Vanderburgh 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.

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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 Vanderburgh County, IN. 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.