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When to Plant Kohlrabi in Cameron County, TX

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.

Cameron County, Texas is in USDA Zone 9b. The average last spring frost is February 4 and the first fall frost is December 22, giving you a growing season of approximately 321 days.

At an elevation of 4,025 feet, Cameron County receives approximately 58.6 inches of rainfall annually with predominantly loam soil. Summer highs average 103ยฐF, 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.

Cameron County, TX (Zone 9b) Year-round
321 days
Last Spring Frost February 4
321 growing days
First Fall Frost December 22

Cameron County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (249 days to spare)
Start indoors: Dec 20 Transplant: Jan 17 🍅 Harvest: Mar 7 – Apr 11
Recommended (50%) ✓ Fits season (237 days to spare)
Start indoors: Jan 7 Transplant: Feb 4 🍅 Harvest: Mar 25 – Apr 29
Safe Start (90%) ✓ Fits season (214 days to spare)
Start indoors: Feb 4 Transplant: Mar 4 🍅 Harvest: Apr 22 – May 27

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 Cameron County

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

Soil pH

Your soil pH (6.7โ€“7.8) overlaps with Kohlrabi's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Cameron County is excellent for Kohlrabi โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.2%). 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

8
successive plantings in your 321-day season

Sow every 5.1 weeks. Last sowing by Oct 18 to harvest before frost.

For a dedicated fall crop, sow by Oct 27.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb 3" 2.2" 0.8" ๐Ÿ’ง Light watering
Mar 3" 3.1" 0" โœ… Rainfall sufficient
Apr 3" 6.1" 0" โœ… Rainfall sufficient
May 3" 9.2" 0" โœ… Rainfall sufficient
Jun 3" 9.1" 0" โœ… Rainfall sufficient
Jul 3" 7.5" 0" โœ… Rainfall sufficient
Aug 3" 6.9" 0" โœ… Rainfall sufficient
Sep 3" 5.6" 0" โœ… Rainfall sufficient
Oct 3" 3.8" 0" โœ… Rainfall sufficient
Nov 3" 2.1" 0.9" ๐Ÿ’ง Light watering
Dec 3" 1.4" 1.6" ๐Ÿšฟ Regular watering

Water needs are for active growing months only (Febโ€“Dec in Cameron 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 ~1,499 GDD — county provides 8,774 GDD Excellent fit

Kohlrabi Planting Timeline โ€” Cameron County, TX

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors January 7 Jan 7 โ€“ Jan 21
Transplant Outdoors February 4 Feb 4 โ€“ Feb 18
Direct Sow January 14 Jan 14 โ€“ Feb 4
Harvest March 25 Mar 25 โ€“ Apr 29
Fall Sowing October 27 Oct 27 โ€“ Nov 10

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

45โ€“65 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9b

๐Ÿ“† Growing Season

321 days in Cameron County

Growing Tips for Kohlrabi in Cameron County

Direct sow Kohlrabi outdoors after February 04 in Cameron County when soil has warmed and frost danger has passed.

With summer highs reaching 103ยฐF in Cameron County, provide afternoon shade for Kohlrabi and water deeply in the morning.

Your generous 322.0-day season in Cameron 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 Cameron County, TX?

Cameron County is in Zone 9b with an average last frost of February 4. Plan your Kohlrabi planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Cameron County, TX?

Cameron County, Texas is in USDA Hardiness Zone 9b. The average last spring frost is February 4 and first fall frost is December 22.

๐ŸŒฑ

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Cameron County, TX. Local conditions may vary. Last updated: April 2026.