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When to Plant Napa Cabbage in Caroline County, MD

Caroline County, Maryland Zone 7b May

Caroline County, Maryland gardeners: here's your May plan

If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 4
Avg. first frost November 4
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14.1 hrs
  1. Time to start napa cabbage inside

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Start harvesting napa cabbage

    If you can't use it all right away, check the food-preservation section of your planner.

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.

Caroline County, Maryland is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 4, giving you a growing season of approximately 214 days.

At an elevation of 469 feet, Caroline County receives approximately 40.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Napa Cabbage during the growing season.

Caroline County, MD (Zone 7b) Long season
214 days
Last Spring Frost April 4
214 growing days
First Fall Frost November 4

Caroline County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Feb 22 Transplant: Mar 29 🍅 Harvest: May 24 – Jun 28
Recommended (50%) ✓ Fits season (123 days to spare)
Start indoors: Feb 28 Transplant: Apr 4 🍅 Harvest: May 30 – Jul 4
Safe Start (90%) ✓ Fits season (117 days to spare)
Start indoors: Mar 18 Transplant: Apr 22 🍅 Harvest: Jun 17 – Jul 22

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 Caroline County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Napa Cabbage's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Napa Cabbage.

Organic Matter

Organic matter is moderate (3.2%). 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 214-day season

Sow every 6.3 weeks. Last sowing by Aug 21 to harvest before frost.

For a dedicated fall crop, sow by Aug 26.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 497 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 2.6" 0" ❄️ Dormant
Feb 2.4" 0" ❄️ Dormant
Mar 3.3" 0" ❄️ Dormant
Apr 6.5" 4" 2.5" 💧 Light watering
May 6.5" 3.8" 2.7" 💧 Light watering
Jun 6.5" 4" 2.5" 💧 Light watering
Jul 6.5" 4.1" 2.4" 💧 Light watering
Aug 6.5" 3.5" 3" 💧 Light watering
Sep 6.5" 3.2" 3.3" 🚿 Regular watering
Oct 6.5" 3.4" 3.1" 💧 Light watering
Nov 6.5" 3.1" 3.4" 🚿 Regular watering
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Caroline 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 ~1,040 GDD — county provides 3,424 GDD Excellent fit

Napa Cabbage Planting Timeline — Caroline County, MD

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors April 4 Apr 4 – Apr 18
Direct Sow March 21 Mar 21 – Apr 11
Harvest May 30 May 30 – Jul 4
Fall Sowing August 26 Aug 26 – Sep 9

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

214 days in Caroline County

Growing Tips for Napa Cabbage in Caroline County

Direct sow Napa Cabbage outdoors after April 04 in Caroline 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 Caroline County, MD?

Caroline County is in Zone 7b with an average last frost of April 4. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Caroline County, MD?

Caroline County, Maryland is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 4.

🌱

Your Caroline County Garden Planner — Free

A 24-page printable planner built for Caroline County (Zone 7b). 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 Caroline County, MD. 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.