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When to Plant Napa Cabbage in Jasper County, SC

Jasper County, South Carolina Zone 9a May

May in the garden — Jasper County, South Carolina

We've pulled the most time-sensitive tasks for Jasper County, South Carolina this May and put them front and centre. Tackle them in order.

Avg. last frost March 15
Avg. first frost November 12
Soil temp (4") 74°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Harvest napa cabbage as they ripen

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

June will be here before you know it — start on
  • 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.

Jasper County, South Carolina is in USDA Zone 9a. The average last spring frost is March 15 and the first fall frost is November 12, giving you a growing season of approximately 242 days.

At an elevation of 143 feet, Jasper County receives approximately 60.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 97°F, so Napa Cabbage may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Napa Cabbage will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Napa Cabbage root diseases.

Jasper County, SC (Zone 9a) Long season
242 days
Last Spring Frost March 15
242 growing days
First Fall Frost November 12
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Jasper County Soil Profile

Soil Type

Sandy Loam

Soil pH

4.8-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (154 days to spare)
Start indoors: Feb 6 Transplant: Mar 6 🍅 Harvest: May 1 – Jun 5
Recommended (50%) ✓ Fits season (151 days to spare)
Start indoors: Feb 15 Transplant: Mar 15 🍅 Harvest: May 10 – Jun 14
Safe Start (90%) ✓ Fits season (146 days to spare)
Start indoors: Mar 12 Transplant: Apr 9 🍅 Harvest: Jun 4 – Jul 9

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 (4.8–6.2) is more acidic than Napa Cabbage prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Jasper County warms quickly in spring but drains fast. Napa Cabbage will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Napa Cabbage.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Napa Cabbage.

How to Plant Napa Cabbage

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

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Napa Cabbage

5
successive plantings in your 242-day season

Sow every 6.3 weeks. Last sowing by Aug 29 to harvest before frost.

For a dedicated fall crop, sow by Sep 17.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 15 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 4.6" 0" ❄️ Dormant
Feb 4.8" 0" ❄️ Dormant
Mar 6.5" 5.7" 0.8" 💧 Light watering
Apr 6.5" 4.3" 2.2" 💧 Light watering
May 6.5" 5.5" 1" 💧 Light watering
Jun 6.5" 5.2" 1.3" 💧 Light watering
Jul 6.5" 5.8" 0.7" 💧 Light watering
Aug 6.5" 5.1" 1.4" 💧 Light watering
Sep 6.5" 5" 1.5" 💧 Light watering
Oct 6.5" 3.5" 3" 💧 Light watering
Nov 6.5" 5.3" 1.2" 💧 Light watering
Dec 5.2" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov 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 ~1,479 GDD — county provides 5,505 GDD Excellent fit

Napa Cabbage Planting Timeline — Jasper County, SC

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors March 15 Mar 15 – Mar 29
Direct Sow February 22 Feb 22 – Mar 15
Harvest May 10 May 10 – Jun 14
Fall Sowing September 17 Sep 17 – Oct 1

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1.5"/week · Only during dry spells

📅 Days to Maturity

55–75 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

242 days in Jasper County

Growing Tips for Napa Cabbage in Jasper County

Direct sow Napa Cabbage outdoors after March 15 in Jasper County when soil has warmed and frost danger has passed.

Sandy soil in Jasper County dries quickly — mulch Napa Cabbage with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 97°F in Jasper County, provide afternoon shade for Napa Cabbage and water deeply in the morning.

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, SC?

Jasper County is in Zone 9a with an average last frost of March 15. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jasper County, SC?

Jasper County, South Carolina is in USDA Hardiness Zone 9a. The average last spring frost is March 15 and first fall frost is November 12.

🌱

Your Jasper County Garden Planner — Free

A 24-page printable planner built for Jasper County (Zone 9a). 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, SC. 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.