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When to Plant Napa Cabbage in Vermillion County, IN

Vermillion County, Indiana Zone 6a May

This month in Vermillion County, Indiana

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

Avg. last frost April 14
Avg. first frost October 16
Soil temp (4") 62°F
Watering Low
Pest pressure Low
Daylight 14.2 hrs
  1. Time to start napa cabbage 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.

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.

Vermillion County, Indiana is in USDA Zone 6a. The average last spring frost is April 14 and the first fall frost is October 16, giving you a growing season of approximately 185 days.

At an elevation of 719 feet, Vermillion County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Napa Cabbage during the growing season.

Vermillion County, IN (Zone 6a) Moderate season
185 days
Last Spring Frost April 14
185 growing days
First Fall Frost October 16

Vermillion County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (92 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jun 6 – Jul 11
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Mar 10 Transplant: Apr 14 🍅 Harvest: Jun 9 – Jul 14
Safe Start (90%) ✓ Fits season (89 days to spare)
Start indoors: Mar 29 Transplant: May 3 🍅 Harvest: Jun 28 – Aug 2

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 Vermillion County

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

Soil pH

Your soil pH (5.9–7.1) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Napa Cabbage is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is excellent (4.4%) — Napa Cabbage will thrive.

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

3
successive plantings in your 185-day season

Sow every 6.3 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Aug 07.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,794 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 1.5" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 6.5" 3.2" 3.3" 🚿 Regular watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.4" 2.1" 💧 Light watering
Jul 6.5" 4.5" 2" 💧 Light watering
Aug 6.5" 4.5" 2" 💧 Light watering
Sep 6.5" 3.6" 2.9" 💧 Light watering
Oct 6.5" 3" 3.5" 🚿 Regular watering
Nov 2.6" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Vermillion 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 ~1,186 GDD — county provides 3,376 GDD Excellent fit

Napa Cabbage Planting Timeline — Vermillion County, IN

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 – Mar 24
Transplant Outdoors April 14 Apr 14 – Apr 28
Direct Sow March 31 Mar 31 – Apr 21
Harvest June 9 Jun 9 – Jul 14
Fall Sowing August 7 Aug 7 – Aug 21

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 6a

📆 Growing Season

185 days in Vermillion County

Growing Tips for Napa Cabbage in Vermillion County

Direct sow Napa Cabbage outdoors after April 14 in Vermillion 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.

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 Vermillion County, IN?

Vermillion County is in Zone 6a with an average last frost of April 14. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Vermillion County, IN?

Vermillion County, Indiana is in USDA Hardiness Zone 6a. The average last spring frost is April 14 and first fall frost is October 16.

🌱

Your Vermillion County Garden Planner — Free

A 24-page printable planner built for Vermillion County (Zone 6a). 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 Vermillion County, IN. 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.