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When to Plant Kohlrabi in Clay County, FL

Clay County, Florida Zone 9a May

What to do in May

Your Clay County, Florida garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost February 18
Avg. first frost November 27
Soil temp (4") 78°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Collect kohlrabi at their peak

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

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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.

Clay County, Florida is in USDA Zone 9a. The average last spring frost is February 18 and the first fall frost is November 27, giving you a growing season of approximately 282 days.

At an elevation of 122 feet, Clay County receives approximately 54.3 inches of rainfall annually with predominantly sand soil. Summer highs average 99°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.

Clay County, FL (Zone 9a) Year-round
282 days
Last Spring Frost February 18
282 growing days
First Fall Frost November 27

Clay County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (197 days to spare)
Start indoors: Jan 12 Transplant: Feb 9 🍅 Harvest: Mar 30 – May 4
Recommended (50%) ✓ Fits season (198 days to spare)
Start indoors: Jan 21 Transplant: Feb 18 🍅 Harvest: Apr 8 – May 13
Safe Start (90%) ✓ Fits season (189 days to spare)
Start indoors: Feb 22 Transplant: Mar 22 🍅 Harvest: May 10 – Jun 14

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 Clay County

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

Soil pH

Your soil pH (5.0–5.8) is more acidic than Kohlrabi prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Clay 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 (1.6%). 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 282-day season

Sow every 5.1 weeks. Last sowing by Sep 23 to harvest before frost.

For a dedicated fall crop, sow by Oct 02.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 262 gal / 100 sq ft

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 2.6" 0" ❄️ Dormant
Feb 3" 3" 0" ✅ Rainfall sufficient
Mar 3" 3.1" 0" ✅ Rainfall sufficient
Apr 3" 2.5" 0.5" 💧 Light watering
May 3" 4" 0" ✅ Rainfall sufficient
Jun 3" 8.5" 0" ✅ Rainfall sufficient
Jul 3" 7.4" 0" ✅ Rainfall sufficient
Aug 3" 7.4" 0" ✅ Rainfall sufficient
Sep 3" 6.6" 0" ✅ Rainfall sufficient
Oct 3" 5.1" 0" ✅ Rainfall sufficient
Nov 3" 2.1" 0.9" 💧 Light watering
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Clay 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 ~1,334 GDD — county provides 6,862 GDD Excellent fit

Kohlrabi Planting Timeline — Clay County, FL

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors January 21 Jan 21 – Feb 4
Transplant Outdoors February 18 Feb 18 – Mar 4
Direct Sow January 28 Jan 28 – Feb 18
Harvest April 8 Apr 8 – May 13
Fall Sowing October 2 Oct 2 – Oct 16

Plant 0.5" deep · 4" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

45–65 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

282 days in Clay County

Growing Tips for Kohlrabi in Clay County

Direct sow Kohlrabi outdoors after February 18 in Clay County when soil has warmed and frost danger has passed.

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

With summer highs reaching 99°F in Clay County, provide afternoon shade for Kohlrabi and water deeply in the morning.

Your generous 283.0-day season in Clay 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 Clay County, FL?

Clay County is in Zone 9a with an average last frost of February 18. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clay County, FL?

Clay County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 18 and first fall frost is November 27.

🌱

Your Clay County Garden Planner — Free

A 24-page printable planner built for Clay 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 Clay 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.