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When to Plant Napa Cabbage in Cotton County, OK

Cotton County, Oklahoma Zone 8a May

May in Cotton County, Oklahoma — your action list

Your garden in Cotton County, Oklahoma is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost March 25
Avg. first frost November 10
Soil temp (4") 66°F
Watering High
Pest pressure Moderate
Daylight 13.8 hrs
  1. Collect napa cabbage at their peak

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in June — start thinking about
  • First harvests: napa cabbage

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Napa cabbage forms tall, barrel-shaped heads with tender, crinkled leaves and a mild, slightly sweet flavor. It is the primary cabbage used for kimchi.

Cotton County, Oklahoma is in USDA Zone 8a. The average last spring frost is March 25 and the first fall frost is November 10, giving you a growing season of approximately 230 days.

At an elevation of 1,015 feet, Cotton County receives approximately 20.6 inches of rainfall annually with predominantly loam soil. Summer highs average 92°F, providing good warmth for Napa Cabbage during the growing season.

Cotton County, OK (Zone 8a) Long season
230 days
Last Spring Frost March 25
230 growing days
First Fall Frost November 10
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Cotton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (140 days to spare)
Start indoors: Feb 7 Transplant: Mar 14 🍅 Harvest: May 9 – Jun 13
Recommended (50%) ✓ Fits season (139 days to spare)
Start indoors: Feb 18 Transplant: Mar 25 🍅 Harvest: May 20 – Jun 24
Safe Start (90%) ✓ Fits season (132 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: Jun 10 – Jul 15

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 Cotton County

How your county's soil matches Napa Cabbage's growing requirements.

Soil pH

Your soil pH (6.3–7.5) is within Napa Cabbage's preferred range (6.0–7.5).

Soil Texture

The loam soil in Cotton County is excellent for Napa Cabbage — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.8%). Annual compost additions will help Napa Cabbage.

How to Plant Napa Cabbage

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Succession Planting Napa Cabbage

4
successive plantings in your 230-day season

Sow every 6.3 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Sep 01.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 2,300 gal / 100 sq ft

Monthly Watering Guide for Napa Cabbage

Napa Cabbage needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Napa Cabbage Needs Rainfall You Supplement Action
Jan 0.5" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 6.5" 1.4" 5.1" 🚿 Regular watering
Apr 6.5" 2.2" 4.3" 🚿 Regular watering
May 6.5" 2.7" 3.8" 🚿 Regular watering
Jun 6.5" 2.9" 3.6" 🚿 Regular watering
Jul 6.5" 2.9" 3.6" 🚿 Regular watering
Aug 6.5" 2.6" 3.9" 🚿 Regular watering
Sep 6.5" 1.9" 4.6" 🚿 Regular watering
Oct 6.5" 1.5" 5" 🚿 Regular watering
Nov 6.5" 0.8" 5.7" 🚿 Regular watering
Dec 0.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Cotton County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Napa Cabbage 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.

Napa Cabbage needs ~1,235 GDD — county provides 4,370 GDD Excellent fit

Napa Cabbage Planting Timeline — Cotton County, OK

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 11 Mar 11 – Apr 1
Harvest May 20 May 20 – Jun 24
Fall Sowing September 1 Sep 1 – Sep 15

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · 2-3 times/week

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 8a

📆 Growing Season

230 days in Cotton County

Growing Tips for Napa Cabbage in Cotton County

Direct sow Napa Cabbage outdoors after March 25 in Cotton County when soil has warmed and frost danger has passed.

Common pests for Napa Cabbage in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Cotton County receives only 21" of rain annually. Napa Cabbage needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Best grown as a fall crop. Direct sow in late summer, 60-70 days before first frost. Keep soil evenly moist. Bolt-resistant varieties are available for spring planting.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Napa Cabbage in Cotton County, OK?

Cotton County is in Zone 8a with an average last frost of March 25. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Cotton County, OK?

Cotton County, Oklahoma is in USDA Hardiness Zone 8a. The average last spring frost is March 25 and first fall frost is November 10.

🌱

Your Cotton County Garden Planner — Free

A 24-page printable planner built for Cotton 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.

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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 Cotton 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.