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When to Plant Kohlrabi in Madison County, FL

Madison County, Florida Zone 9a May

Your May planting checklist for Madison County, Florida

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

Avg. last frost March 5
Avg. first frost November 25
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. It's harvest week for kohlrabi

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

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Kohlrabi is an unusual brassica that forms a swollen stem above ground with a mild, sweet turnip-like flavor. Both the bulb and tender leaves are edible.

Madison County, Florida is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 25, giving you a growing season of approximately 265 days.

At an elevation of 434 feet, Madison County receives approximately 61.2 inches of rainfall annually with predominantly sand soil. Summer highs average 95°F, so Kohlrabi may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Kohlrabi will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.

Madison County, FL (Zone 9a) Long season
265 days
Last Spring Frost March 5
265 growing days
First Fall Frost November 25

Madison County Soil Profile

Soil Type

Sand

Soil pH

5.2-5.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (180 days to spare)
Start indoors: Jan 27 Transplant: Feb 24 🍅 Harvest: Apr 14 – May 19
Recommended (50%) ✓ Fits season (181 days to spare)
Start indoors: Feb 5 Transplant: Mar 5 🍅 Harvest: Apr 23 – May 28
Safe Start (90%) ✓ Fits season (184 days to spare)
Start indoors: Feb 25 Transplant: Mar 25 🍅 Harvest: May 13 – Jun 17

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 Madison County

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

Soil pH

Your soil pH (5.2–5.7) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Kohlrabi.

How to Plant Kohlrabi

0.5"
Planting Depth
4"
Between Plants
12"
Between Rows

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

Succession Planting Kohlrabi

7
successive plantings in your 265-day season

Sow every 5.1 weeks. Last sowing by Sep 21 to harvest before frost.

For a dedicated fall crop, sow by Sep 30.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Kohlrabi

Kohlrabi needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Kohlrabi Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 3" 3.8" 0" ✅ Rainfall sufficient
Apr 3" 3.1" 0" ✅ Rainfall sufficient
May 3" 4.1" 0" ✅ Rainfall sufficient
Jun 3" 7.7" 0" ✅ Rainfall sufficient
Jul 3" 8" 0" ✅ Rainfall sufficient
Aug 3" 9.6" 0" ✅ Rainfall sufficient
Sep 3" 8.6" 0" ✅ Rainfall sufficient
Oct 3" 4.6" 0" ✅ Rainfall sufficient
Nov 3" 2.4" 0.6" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Madison County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Kohlrabi 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.

Kohlrabi needs ~1,169 GDD — county provides 5,631 GDD Excellent fit

Kohlrabi Planting Timeline — Madison County, FL

Kohlrabi 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 23 Apr 23 – May 28
Fall Sowing September 30 Sep 30 – Oct 14

Plant 0.5" deep · 4" 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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

265 days in Madison County

Growing Tips for Kohlrabi in Madison County

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

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

Your generous 265.0-day season in Madison County allows multiple plantings of Kohlrabi. Sow every 22.0 days for continuous harvest.

Common pests for Kohlrabi in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest when bulbs are 2-3 inches in diameter for best texture and flavor. Larger bulbs may become woody and fibrous.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Kohlrabi in Madison County, FL?

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

What planting zone is Madison County, FL?

Madison County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 25.

🌱

Your Madison County Garden Planner — Free

A 24-page printable planner built for Madison 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 Madison 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.