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When to Plant Napa Cabbage in Spink County, SD

Spink County, South Dakota Zone 4b May

Your May planting checklist for Spink County, South Dakota

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Spink County, South Dakota.

Avg. last frost May 10
Avg. first frost October 1
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Move napa cabbage into the garden

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Sow napa cabbage where they'll grow

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

To set up a strong June, finish these tasks
  • Starting indoors: 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.

Spink County, South Dakota is in USDA Zone 4b. The average last spring frost is May 10 and the first fall frost is October 1, giving you a growing season of approximately 144 days.

At an elevation of 818 feet, Spink County receives approximately 31.4 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Napa Cabbage to ensure they mature before fall.

Spink County, SD (Zone 4b) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1
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Spink County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Mar 20 Transplant: May 1 🍅 Harvest: Jun 26 – Jul 31
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jul 5 – Aug 9
Safe Start (90%) ✓ Fits season (55 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Jul 14 – Aug 18

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 Spink County

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

Soil pH

Your soil pH (6.7–7.3) is within Napa Cabbage's preferred range (6.0–7.5).

Soil Texture

The loam soil in Spink 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 moderate (3.4%). Annual compost additions will help Napa Cabbage.

How to Plant Napa Cabbage

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

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Napa Cabbage

3
successive plantings in your 144-day season

Sow every 6.3 weeks. Last sowing by Jul 18 to harvest before frost.

For a dedicated fall crop, sow by Jul 09.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.9″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,590 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 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 2.2" 0" ❄️ Dormant
Apr 2.9" 0" ❄️ Dormant
May 6.5" 5.3" 1.2" 💧 Light watering
Jun 6.5" 4.5" 2" 💧 Light watering
Jul 6.5" 3.6" 2.9" 💧 Light watering
Aug 6.5" 4.1" 2.4" 💧 Light watering
Sep 6.5" 2.7" 3.8" 🚿 Regular watering
Oct 6.5" 2.3" 4.2" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 0.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Spink 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 ~699 GDD — county provides 1,548 GDD Excellent fit

Napa Cabbage Planting Timeline — Spink County, SD

Napa Cabbage Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest July 5 Jul 5 – Aug 9
Fall Sowing July 9 Jul 9 – Jul 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Transplant Outdoors Direct Sow
June
July Fall Sowing Harvest
August Harvest
September
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 4b

📆 Growing Season

144 days in Spink County

Growing Tips for Napa Cabbage in Spink County

Direct sow Napa Cabbage outdoors after May 10 in Spink 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 Spink County, SD?

Spink County is in Zone 4b with an average last frost of May 10. Plan your Napa Cabbage planting based on this frost date — see the calendar above for exact timing.

What planting zone is Spink County, SD?

Spink County, South Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 10 and first fall frost is October 1.

🌱

Your Spink County Garden Planner — Free

A 24-page printable planner built for Spink County (Zone 4b). 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 Spink County, SD. 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.