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When to Plant Watercress in DeKalb County, GA

DeKalb County, Georgia Zone 8a May

May in the garden — DeKalb County, Georgia

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

Avg. last frost March 22
Avg. first frost November 13
Soil temp (4") 67°F
Watering Moderate
Pest pressure Moderate
Daylight 13.8 hrs
  1. Basket week: watercress

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

Looking ahead to June
  • 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.

DeKalb County, Georgia is in USDA Zone 8a. The average last spring frost is March 22 and the first fall frost is November 13, giving you a growing season of approximately 236 days.

At an elevation of 323 feet, DeKalb County receives approximately 50.3 inches of rainfall annually with predominantly clay loam soil. Summer highs average 94°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.

DeKalb County, GA (Zone 8a) Long season
236 days
Last Spring Frost March 22
236 growing days
First Fall Frost November 13
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DeKalb County Soil Profile

Soil Type

Clay Loam

Soil pH

5.7-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (161 days to spare)
Start indoors: Feb 4 Transplant: Mar 11 🍅 Harvest: Apr 22 – May 27
Recommended (50%) ✓ Fits season (159 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: May 3 – Jun 7
Safe Start (90%) ✓ Fits season (157 days to spare)
Start indoors: Mar 6 Transplant: Apr 10 🍅 Harvest: May 22 – Jun 26

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 DeKalb County

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

Soil pH

Your soil pH (5.7–6.6) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

The clay loam soil in DeKalb County is excellent for Watercress — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.3%). 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 236-day season

Sow every 4.6 weeks. Last sowing by Sep 14 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
0.7″/week
Watering frequency 2-3 times/week
Season total 1,524 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 4.8" 0" ❄️ Dormant
Feb 4.4" 0" ❄️ Dormant
Mar 6.5" 5.1" 1.4" 💧 Light watering
Apr 6.5" 3.8" 2.7" 💧 Light watering
May 6.5" 3.6" 2.9" 💧 Light watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 5.7" 0.8" 💧 Light watering
Aug 6.5" 4.5" 2" 💧 Light watering
Sep 6.5" 3.5" 3" 💧 Light watering
Oct 6.5" 3.1" 3.4" 🚿 Regular watering
Nov 6.5" 3.8" 2.7" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in DeKalb 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 ~1,025 GDD — county provides 4,838 GDD Excellent fit

Watercress Planting Timeline — DeKalb County, GA

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 8 Mar 8 – Mar 29
Harvest May 3 May 3 – Jun 7
Fall Sowing September 4 Sep 4 – Sep 18

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors
May Harvest
June Harvest
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 8a

📆 Growing Season

236 days in DeKalb County

Growing Tips for Watercress in DeKalb County

Direct sow Watercress outdoors after March 22 in DeKalb County when soil has warmed and frost danger has passed.

With DeKalb County's clay soil (33% clay), work in 3-4 inches of compost before planting Watercress. Avoid tilling when soil is wet to prevent compaction.

Your generous 236.0-day season in DeKalb 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 DeKalb County, GA?

DeKalb County is in Zone 8a with an average last frost of March 22. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is DeKalb County, GA?

DeKalb County, Georgia is in USDA Hardiness Zone 8a. The average last spring frost is March 22 and first fall frost is November 13.

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Your DeKalb County Garden Planner — Free

A 24-page printable planner built for DeKalb County (Zone 8a). 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 DeKalb County, GA. 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.