Blog

When to Plant Watercress in Hamilton County, TX

Hamilton County, Texas Zone 8b May

Your May gardening checklist

A quick May briefing for Hamilton County, Texas gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 18
Avg. first frost November 12
Soil temp (4") 61°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
  1. Basket week: watercress

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

June prep starts now
  • 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.

Hamilton County, Texas is in USDA Zone 8b. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 4,378 feet, Hamilton County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 93°F, providing good warmth for Watercress during the growing season. Clay soil retains moisture well for Watercress, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Watercress root diseases.

Hamilton County, TX (Zone 8b) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12
Share this guide:

Hamilton County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (167 days to spare)
Start indoors: Jan 31 Transplant: Mar 7 🍅 Harvest: Apr 18 – May 23
Recommended (50%) ✓ Fits season (162 days to spare)
Start indoors: Feb 11 Transplant: Mar 18 🍅 Harvest: Apr 29 – Jun 3
Safe Start (90%) ✓ Fits season (157 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 23 – Jun 27

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 Hamilton County

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

Soil pH

Your soil pH (6.9–8.2) is more alkaline than Watercress prefers (6.5–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Hamilton County is workable for Watercress. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (3.4%). 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 239-day season

Sow every 4.6 weeks. Last sowing by Sep 13 to harvest before frost.

For a dedicated fall crop, sow by Sep 03.

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 904 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 1.6" 0" ❄️ Dormant
Feb 2.2" 0" ❄️ Dormant
Mar 6.5" 3.8" 2.7" 💧 Light watering
Apr 6.5" 6.9" 0" ✅ Rainfall sufficient
May 6.5" 9.7" 0" ✅ Rainfall sufficient
Jun 6.5" 10.8" 0" ✅ Rainfall sufficient
Jul 6.5" 8.7" 0" ✅ Rainfall sufficient
Aug 6.5" 8.5" 0" ✅ Rainfall sufficient
Sep 6.5" 5.7" 0.8" 💧 Light watering
Oct 6.5" 3.7" 2.8" 💧 Light watering
Nov 6.5" 2.2" 4.3" 🚿 Regular watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Hamilton 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 ~988 GDD — county provides 4,720 GDD Excellent fit

Watercress Planting Timeline — Hamilton County, TX

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 4 Mar 4 – Mar 25
Harvest April 29 Apr 29 – Jun 3
Fall Sowing September 3 Sep 3 – Sep 17

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Harvest
May Harvest
June Harvest
July
August
September Fall Sowing
October
November
December
Share this guide:

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_alkaline

🗺️ USDA Zone

Zone 8b

📆 Growing Season

239 days in Hamilton County

Growing Tips for Watercress in Hamilton County

Direct sow Watercress outdoors after March 18 in Hamilton County when soil has warmed and frost danger has passed.

With Hamilton County's clay soil (40% clay), work in 3-4 inches of compost before planting Watercress. Avoid tilling when soil is wet to prevent compaction.

Your generous 239.0-day season in Hamilton 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 Hamilton County, TX?

Hamilton County is in Zone 8b with an average last frost of March 18. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hamilton County, TX?

Hamilton County, Texas is in USDA Hardiness Zone 8b. The average last spring frost is March 18 and first fall frost is November 12.

🌱

Your Hamilton County Garden Planner — Free

A 24-page printable planner built for Hamilton 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.

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 Hamilton 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.