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When to Plant Kohlrabi in Jackson County, TX

Jackson County, Texas Zone 9b May

This month in Jackson County, Texas

Your Jackson County, Texas 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 21
Avg. first frost December 5
Soil temp (4") 76°F
Watering Low
Pest pressure High
Daylight 13.4 hrs
  1. Harvest kohlrabi as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

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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.

Jackson County, Texas is in USDA Zone 9b. The average last spring frost is February 21 and the first fall frost is December 5, giving you a growing season of approximately 287 days.

At an elevation of 286 feet, Jackson County receives approximately 64.3 inches of rainfall annually with predominantly loam soil. Summer highs average 103°F, so Kohlrabi may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Kohlrabi root diseases.

Jackson County, TX (Zone 9b) Year-round
287 days
Last Spring Frost February 21
287 growing days
First Fall Frost December 5
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Jackson County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (205 days to spare)
Start indoors: Jan 11 Transplant: Feb 8 🍅 Harvest: Mar 29 – May 3
Recommended (50%) ✓ Fits season (203 days to spare)
Start indoors: Jan 24 Transplant: Feb 21 🍅 Harvest: Apr 11 – May 16
Safe Start (90%) ✓ Fits season (195 days to spare)
Start indoors: Feb 14 Transplant: Mar 14 🍅 Harvest: May 2 – Jun 6

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 Jackson County

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

Soil pH

Your soil pH (6.5–7.2) is within Kohlrabi's preferred range (6.0–7.5).

Soil Texture

The loam soil in Jackson County is excellent for Kohlrabi — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Kohlrabi.

Organic Matter

Organic matter is moderate (2.0%). Annual compost additions will help 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 287-day season

Sow every 5.1 weeks. Last sowing by Oct 01 to harvest before frost.

For a dedicated fall crop, sow by Oct 10.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 1.7" 0" ❄️ Dormant
Feb 3" 2.1" 0.9" 💧 Light watering
Mar 3" 3.9" 0" ✅ Rainfall sufficient
Apr 3" 6.5" 0" ✅ Rainfall sufficient
May 3" 9" 0" ✅ Rainfall sufficient
Jun 3" 10.4" 0" ✅ Rainfall sufficient
Jul 3" 7.9" 0" ✅ Rainfall sufficient
Aug 3" 8" 0" ✅ Rainfall sufficient
Sep 3" 6" 0" ✅ Rainfall sufficient
Oct 3" 4.8" 0" ✅ Rainfall sufficient
Nov 3" 2.3" 0.7" 💧 Light watering
Dec 3" 1.7" 1.3" 💧 Light watering

Water needs are for active growing months only (Feb–Dec in Jackson 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 ~1,499 GDD — county provides 7,848 GDD Excellent fit

Kohlrabi Planting Timeline — Jackson County, TX

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors January 24 Jan 24 – Feb 7
Transplant Outdoors February 21 Feb 21 – Mar 7
Direct Sow January 31 Jan 31 – Feb 21
Harvest April 11 Apr 11 – May 16
Fall Sowing October 10 Oct 10 – Oct 24

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
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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: ideal

🗺️ USDA Zone

Zone 9b

📆 Growing Season

287 days in Jackson County

Growing Tips for Kohlrabi in Jackson County

Direct sow Kohlrabi outdoors after February 21 in Jackson County when soil has warmed and frost danger has passed.

With summer highs reaching 103°F in Jackson County, provide afternoon shade for Kohlrabi and water deeply in the morning.

Your generous 288.0-day season in Jackson 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 Jackson County, TX?

Jackson County is in Zone 9b with an average last frost of February 21. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jackson County, TX?

Jackson County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 21 and first fall frost is December 5.

🌱

Your Jackson County Garden Planner — Free

A 24-page printable planner built for Jackson County (Zone 9b). 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 Jackson County, TX. 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.