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When to Plant Kohlrabi in Hernando County, FL

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.

Hernando County, Florida is in USDA Zone 9a. The average last spring frost is January 25 and the first fall frost is December 16, giving you a growing season of approximately 325 days.

At an elevation of 245 feet, Hernando County receives approximately 51.5 inches of rainfall annually with predominantly sand soil. Summer highs average 99ยฐF, so Kohlrabi may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring โ€” great for early planting โ€” 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.

Hernando County, FL (Zone 9a) Year-round
325 days
Last Spring Frost January 25
325 growing days
First Fall Frost December 16

Hernando County Soil Profile

Soil Type

Sand

Soil pH

5.1-5.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (241 days to spare)
Start indoors: Dec 22 Transplant: Jan 19 🍅 Harvest: Mar 9 – Apr 13
Recommended (50%) ✓ Fits season (241 days to spare)
Start indoors: Dec 28 Transplant: Jan 25 🍅 Harvest: Mar 15 – Apr 19
Safe Start (90%) ✓ Fits season (215 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Apr 18 – May 23

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 Hernando County

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

Soil pH

Your soil pH (5.1โ€“5.9) is more acidic than Kohlrabi prefers (6.0โ€“7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Hernando 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

8
successive plantings in your 325-day season

Sow every 5.1 weeks. Last sowing by Oct 12 to harvest before frost.

For a dedicated fall crop, sow by Oct 21.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.7″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 715 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 3" 2.6" 0.4" ๐Ÿ’ง Light watering
Feb 3" 2.5" 0.5" ๐Ÿ’ง Light watering
Mar 3" 3" 0" โœ… Rainfall sufficient
Apr 3" 2.2" 0.8" ๐Ÿ’ง Light watering
May 3" 3.3" 0" โœ… Rainfall sufficient
Jun 3" 7.1" 0" โœ… Rainfall sufficient
Jul 3" 7.5" 0" โœ… Rainfall sufficient
Aug 3" 6.7" 0" โœ… Rainfall sufficient
Sep 3" 6.8" 0" โœ… Rainfall sufficient
Oct 3" 5.1" 0" โœ… Rainfall sufficient
Nov 3" 2.4" 0.6" ๐Ÿ’ง Light watering
Dec 3" 2.2" 0.8" ๐Ÿ’ง Light watering

Water needs are for active growing months only (Janโ€“Dec in Hernando County). Supplement amounts are based on average rainfall โ€” 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" 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.

Kohlrabi needs ~1,334 GDD — county provides 7,905 GDD Excellent fit

Kohlrabi Planting Timeline โ€” Hernando County, FL

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors December 28 Dec 28 โ€“ Jan 11
Transplant Outdoors January 25 Jan 25 โ€“ Feb 8
Direct Sow January 4 Jan 4 โ€“ Jan 25
Harvest March 15 Mar 15 โ€“ Apr 19
Fall Sowing October 21 Oct 21 โ€“ Nov 4

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

45โ€“65 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

325 days in Hernando County

Growing Tips for Kohlrabi in Hernando County

Direct sow Kohlrabi outdoors after January 25 in Hernando County when soil has warmed and frost danger has passed.

Sandy soil in Hernando County dries quickly โ€” 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 99ยฐF in Hernando County, provide afternoon shade for Kohlrabi and water deeply in the morning.

Your generous 326.0-day season in Hernando 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 Hernando County, FL?

Hernando County is in Zone 9a with an average last frost of January 25. Plan your Kohlrabi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hernando County, FL?

Hernando County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is January 25 and first fall frost is December 16.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hernando County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Hernando County, FL. Local conditions may vary. Last updated: April 2026.