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When to Plant Kohlrabi in Stephens County, OK

Stephens County, Oklahoma Zone 8a May

May in the garden — Stephens County, Oklahoma

May is a pivotal month for Stephens County, Oklahoma gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 6
Avg. first frost November 1
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 13.8 hrs
  1. Get kohlrabi seeds going inside

    A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.

  2. It's harvest week for kohlrabi

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

Before June arrives, get these ready
  • First harvests: kohlrabi

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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.

Stephens County, Oklahoma is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 979 feet, Stephens County receives approximately 26.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90°F, providing good warmth for Kohlrabi during the growing season.

Stephens County, OK (Zone 8a) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Stephens County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (126 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 16 – Jun 20
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Mar 2 Transplant: Apr 6 🍅 Harvest: May 25 – Jun 29
Safe Start (90%) ✓ Fits season (134 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 3 – Jul 8

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 Stephens County

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

Soil pH

Your soil pH (6.3–7.6) overlaps with Kohlrabi's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Kohlrabi will thrive.

How to Plant Kohlrabi

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Kohlrabi

5
successive plantings in your 209-day season

Sow every 5.1 weeks. Last sowing by Aug 28 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 392 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 0.6" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 3" 2.7" 0.3" 💧 Light watering
May 3" 3.9" 0" ✅ Rainfall sufficient
Jun 3" 4.3" 0" ✅ Rainfall sufficient
Jul 3" 3" 0" ✅ Rainfall sufficient
Aug 3" 3.5" 0" ✅ Rainfall sufficient
Sep 3" 2.4" 0.6" 💧 Light watering
Oct 3" 1.9" 1.1" 💧 Light watering
Nov 3" 0.8" 2.2" 🚿 Regular watering
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Stephens 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 ~962 GDD — county provides 3,657 GDD Excellent fit

Kohlrabi Planting Timeline — Stephens County, OK

Kohlrabi Planting Calendar

Activity When Date Range
Start Indoors March 2 Mar 2 – Mar 16
Transplant Outdoors April 6 Apr 6 – Apr 20
Direct Sow March 23 Mar 23 – Apr 13
Harvest May 25 May 25 – Jun 29
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 8a

📆 Growing Season

209 days in Stephens County

Growing Tips for Kohlrabi in Stephens County

Direct sow Kohlrabi outdoors after April 06 in Stephens County when soil has warmed and frost danger has passed.

Your generous 209.0-day season in Stephens 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 Stephens County, OK?

Stephens County is in Zone 8a with an average last frost of April 6. Plan your Kohlrabi planting based on this frost date — see the calendar above for exact timing.

What planting zone is Stephens County, OK?

Stephens County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is November 1.

🌱

Your Stephens County Garden Planner — Free

A 24-page printable planner built for Stephens County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Stephens County, OK. 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.