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When to Plant Watercress in Calhoun County, FL

Calhoun County, Florida Zone 9a May

May to-do list for Calhoun County, Florida

Each item below is timed to Calhoun County, Florida's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost March 5
Avg. first frost November 20
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Basket week: watercress

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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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.

Calhoun County, Florida is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 20, giving you a growing season of approximately 260 days.

At an elevation of 178 feet, Calhoun County receives approximately 61.2 inches of rainfall annually with predominantly sand soil. Summer highs average 93°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.

Calhoun County, FL (Zone 9a) Long season
260 days
Last Spring Frost March 5
260 growing days
First Fall Frost November 20
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Calhoun County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (185 days to spare)
Start indoors: Jan 26 Transplant: Feb 23 🍅 Harvest: Apr 6 – May 11
Recommended (50%) ✓ Fits season (183 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 16 – May 21
Safe Start (90%) ✓ Fits season (183 days to spare)
Start indoors: Feb 27 Transplant: Mar 27 🍅 Harvest: May 8 – Jun 12

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 Calhoun County

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

Soil pH

Your soil pH (4.8–5.7) is more acidic than Watercress prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Calhoun 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 low (1.6%). Add 2-3 inches of compost before planting Watercress.

How to Plant Watercress

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Watercress

7
successive plantings in your 260-day season

Sow every 4.6 weeks. Last sowing by Sep 21 to harvest before frost.

For a dedicated fall crop, sow by Sep 25.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,225 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 2.5" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 6.5" 3.5" 3" 💧 Light watering
Apr 6.5" 3.1" 3.4" 🚿 Regular watering
May 6.5" 4.2" 2.3" 💧 Light watering
Jun 6.5" 9" 0" ✅ Rainfall sufficient
Jul 6.5" 8.8" 0" ✅ Rainfall sufficient
Aug 6.5" 8.4" 0" ✅ Rainfall sufficient
Sep 6.5" 8.6" 0" ✅ Rainfall sufficient
Oct 6.5" 5" 1.5" 💧 Light watering
Nov 6.5" 2.5" 4" 🚿 Regular watering
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Calhoun 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 5,135 GDD Excellent fit

Watercress Planting Timeline — Calhoun County, FL

Watercress Planting Calendar

Activity When Date Range
Start Indoors February 5 Feb 5 – Feb 19
Transplant Outdoors March 5 Mar 5 – Mar 19
Direct Sow February 12 Feb 12 – Mar 5
Harvest April 16 Apr 16 – May 21
Fall Sowing September 25 Sep 25 – Oct 9

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June
July
August
September Fall Sowing
October Fall Sowing
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 9a

📆 Growing Season

260 days in Calhoun County

Growing Tips for Watercress in Calhoun County

Direct sow Watercress outdoors after March 05 in Calhoun County when soil has warmed and frost danger has passed.

Sandy soil in Calhoun 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 260.0-day season in Calhoun 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 Calhoun County, FL?

Calhoun County is in Zone 9a with an average last frost of March 5. Plan your Watercress planting based on this frost date — see the calendar above for exact timing.

What planting zone is Calhoun County, FL?

Calhoun County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 20.

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Your Calhoun County Garden Planner — Free

A 24-page printable planner built for Calhoun County (Zone 9a). 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 Calhoun County, FL. 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.