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When to plant Napa Cabbage in Jasper County, IL

Jasper County's spring Napa Cabbage window runs March 30 through April 20. time plantings around the expected last-frost window for best survival. A second sowing from August 11 to August 25 extends the harvest into fall.

When to Plant Napa Cabbage in Jasper County, IL

Jasper County, Illinois Zone 6b June

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Avg. last frost April 13
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs

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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.

Jasper County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 20, giving you a growing season of approximately 190 days.

At an elevation of 1,384 feet, Jasper County receives approximately 35 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Napa Cabbage during the growing season.

Jasper County, IL (Zone 6b) Moderate season
190 days
Last Spring Frost April 13
190 growing days
First Fall Frost October 20

Jasper County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Napa Cabbage Planting Risk Windows

Early Start (70% safe) ✓ Fits season (99 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: Jun 2 – Jul 7
Recommended (50%) ✓ Fits season (99 days to spare)
Start indoors: Mar 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Jul 13
Safe Start (90%) ✓ Fits season (96 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 22 – Jul 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 Jasper County

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

Soil pH

Your soil pH (5.9–7.3) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.5%) — 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

4
successive plantings in your 190-day season

Sow every 6.3 weeks. Last sowing by Aug 06 to harvest before frost.

For a dedicated fall crop, sow by Aug 11.

Napa Cabbage Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.9″/week
Watering frequency 2-3 times/week
Season total 1,474 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 6.5" 3.1" 3.4" 🚿 Regular watering
May 6.5" 4.1" 2.4" 💧 Light watering
Jun 6.5" 4.7" 1.8" 💧 Light watering
Jul 6.5" 3.3" 3.2" 💧 Light watering
Aug 6.5" 3.5" 3" 💧 Light watering
Sep 6.5" 3.4" 3.1" 💧 Light watering
Oct 6.5" 3" 3.5" 🚿 Regular watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jasper 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 3,467 GDD Excellent fit

Napa Cabbage Planting Timeline — Jasper County, IL

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 – Mar 23
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow March 30 Mar 30 – Apr 20
Harvest June 8 Jun 8 – Jul 13
Fall Sowing August 11 Aug 11 – Aug 25

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 6b

📆 Growing Season

190 days in Jasper County

Growing Tips for Napa Cabbage in Jasper County

Direct sow Napa Cabbage outdoors after April 13 in Jasper 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 Jasper County, IL?

Jasper County is in Zone 6b with an average last frost of April 13. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jasper County, IL?

Jasper County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 20.

When should I plant Napa Cabbage in Jasper County, IL?

In Jasper County, IL, plant Napa Cabbage after the last frost (around April 13) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Jasper County, IL for Napa Cabbage?

Jasper County sits in USDA Zone 6b. Napa Cabbage grows reliably in zones 2a through 11b, so it's a good fit here.

Can Napa Cabbage grow in Jasper County's climate?

Yes — Napa Cabbage grows well in Jasper County's temperate climate. Jasper County averages a 190-day frost-free season, with last frost around April 13 and first frost around October 20.

🌱

Your Jasper County Garden Planner — Free

A 22-page printable planner built for Jasper County (Zone 6b). 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 Jasper County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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