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When to Plant Watercress in Delta County, TX

Delta County, Texas Zone 8b May

May in Delta County, Texas — your action list

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

Avg. last frost March 15
Avg. first frost November 15
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.7 hrs
  1. Harvest watercress as they ripen

    If you can't use it all right away, check the food-preservation section of your planner.

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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.

Delta County, Texas is in USDA Zone 8b. The average last spring frost is March 15 and the first fall frost is November 15, giving you a growing season of approximately 245 days.

At an elevation of 235 feet, Delta County receives approximately 70.9 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91°F, providing good warmth for Watercress during the growing season. Sandy soil warms quickly in spring — great for early planting — but Watercress will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.

Delta County, TX (Zone 8b) Long season
245 days
Last Spring Frost March 15
245 growing days
First Fall Frost November 15
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Delta County Soil Profile

Soil Type

Sandy Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (164 days to spare)
Start indoors: Jan 31 Transplant: Mar 7 🍅 Harvest: Apr 18 – May 23
Recommended (50%) ✓ Fits season (168 days to spare)
Start indoors: Feb 8 Transplant: Mar 15 🍅 Harvest: Apr 26 – May 31
Safe Start (90%) ✓ Fits season (158 days to spare)
Start indoors: Mar 5 Transplant: Apr 9 🍅 Harvest: May 21 – Jun 25

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 Delta County

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

Soil pH

Your soil pH (5.4–6.8) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Delta County warms quickly in spring but drains fast. Watercress will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Watercress is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is moderate (2.2%). 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

7
successive plantings in your 245-day season

Sow every 4.6 weeks. Last sowing by Sep 16 to harvest before frost.

For a dedicated fall crop, sow by Sep 06.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.2″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,602 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 1.8" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 6.5" 4.1" 2.4" 💧 Light watering
Apr 6.5" 6.8" 0" ✅ Rainfall sufficient
May 6.5" 10.6" 0" ✅ Rainfall sufficient
Jun 6.5" 11.2" 0" ✅ Rainfall sufficient
Jul 6.5" 8.2" 0" ✅ Rainfall sufficient
Aug 6.5" 9.9" 0" ✅ Rainfall sufficient
Sep 6.5" 6.7" 0" ✅ Rainfall sufficient
Oct 6.5" 4.6" 1.9" 💧 Light watering
Nov 6.5" 2.3" 4.2" 🚿 Regular watering
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Delta 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 4,471 GDD Excellent fit

Watercress Planting Timeline — Delta County, TX

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 – Feb 22
Transplant Outdoors March 15 Mar 15 – Mar 29
Direct Sow March 1 Mar 1 – Mar 22
Harvest April 26 Apr 26 – May 31
Fall Sowing September 6 Sep 6 – Sep 20

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June
July
August
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 8b

📆 Growing Season

245 days in Delta County

Growing Tips for Watercress in Delta County

Direct sow Watercress outdoors after March 15 in Delta County when soil has warmed and frost danger has passed.

Sandy soil in Delta County dries quickly — mulch Watercress with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 245.0-day season in Delta 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 Delta County, TX?

Delta County is in Zone 8b with an average last frost of March 15. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Delta County, TX?

Delta County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 15 and first fall frost is November 15.

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Your Delta County Garden Planner — Free

A 24-page printable planner built for Delta County (Zone 8b). 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 Delta County, TX. 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.