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When to Plant Watercress in Cullman County, AL

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.

Cullman County, Alabama is in USDA Zone 7a. The average last spring frost is March 28 and the first fall frost is November 2, giving you a growing season of approximately 219 days.

At an elevation of 347 feet, Cullman County receives approximately 53.1 inches of rainfall annually with predominantly clay loam soil. Summer highs average 91ยฐF, 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.

Cullman County, AL (Zone 7a) Long season
219 days
Last Spring Frost March 28
219 growing days
First Fall Frost November 2

Cullman County Soil Profile

Soil Type

Clay Loam

Soil pH

5.4-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (143 days to spare)
Start indoors: Feb 14 Transplant: Mar 21 🍅 Harvest: May 2 – Jun 6
Recommended (50%) ✓ Fits season (142 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 9 – Jun 13
Safe Start (90%) ✓ Fits season (140 days to spare)
Start indoors: Mar 15 Transplant: Apr 19 🍅 Harvest: May 31 – Jul 5

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 Cullman County

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

Soil pH

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

Soil Texture

The clay loam soil in Cullman County is excellent for Watercress โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Watercress.

Organic Matter

Organic matter is moderate (2.7%). 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

6
successive plantings in your 219-day season

Sow every 4.6 weeks. Last sowing by Sep 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 24.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 74 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” 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 โ€” 4" 0" โ„๏ธ Dormant
Feb โ€” 4" 0" โ„๏ธ Dormant
Mar 6.5" 5.3" 1.2" ๐Ÿ’ง Light watering
Apr 6.5" 4.4" 2.1" ๐Ÿ’ง Light watering
May 6.5" 4.3" 2.2" ๐Ÿ’ง Light watering
Jun 6.5" 4.8" 1.7" ๐Ÿ’ง Light watering
Jul 6.5" 5.2" 1.3" ๐Ÿ’ง Light watering
Aug 6.5" 5.4" 1.1" ๐Ÿ’ง Light watering
Sep 6.5" 4" 2.5" ๐Ÿ’ง Light watering
Oct 6.5" 3.3" 3.2" ๐Ÿ’ง Light watering
Nov 6.5" 4.4" 2.1" ๐Ÿ’ง Light watering
Dec โ€” 3.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Cullman County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 3,996 GDD Excellent fit

Watercress Planting Timeline โ€” Cullman County, AL

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 21 Feb 21 โ€“ Mar 7
Transplant Outdoors March 28 Mar 28 โ€“ Apr 11
Direct Sow March 14 Mar 14 โ€“ Apr 4
Harvest May 9 May 9 โ€“ Jun 13
Fall Sowing August 24 Aug 24 โ€“ Sep 7

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June Harvest
July โ€”
August Fall Sowing
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

219 days in Cullman County

Growing Tips for Watercress in Cullman County

Direct sow Watercress outdoors after March 28 in Cullman County when soil has warmed and frost danger has passed.

With Cullman County's clay soil (30% clay), work in 3-4 inches of compost before planting Watercress. Avoid tilling when soil is wet to prevent compaction.

Your generous 219.0-day season in Cullman 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 Cullman County, AL?

Cullman County is in Zone 7a with an average last frost of March 28. Plan your Watercress planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cullman County, AL?

Cullman County, Alabama is in USDA Hardiness Zone 7a. The average last spring frost is March 28 and first fall frost is November 2.

๐ŸŒฑ

Plan Your Garden with Confidence

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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 Cullman County, AL. Local conditions may vary. Last updated: April 2026.