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When to Plant Napa Cabbage in Agate, North Dakota (58310)

Location

Agate, North Dakota

ZIP Code

58310

USDA Zone

3b

Last Frost

Wednesday, May 20, 2026

📅 Your 2026 Planting Dates

Start Seeds Indoors

Wednesday, April 8, 2026

Transplant Outdoors

Wednesday, June 3, 2026

Based on last frost Wednesday, May 20, 2026 · Zone 3b

Pro tip: Start Napa Cabbage seeds indoors 6 weeks before your last frost date, then transplant outdoors around Wednesday, June 3, 2026.

🌿 Plant Details

Scientific Name Brassica rapa subsp. pekinensis
Days to Maturity 70 days
Mature Height 12-18"
Spread 12"

☀️ Growing Requirements

☀️

Sun

Full Sun (6-8 hours)

💧

Water

Regular (1-2 inches/week)

↔️

Spacing

18" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 4-7 days

Ready to Plant Napa Cabbage in Agate?

Get your seeds now so they're ready by Wednesday, April 8, 2026.

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🤝 Good Companions

BeetOnionCeleryCucumber

⚠️ Avoid Planting Near

StrawberryTomatoPepper
🤝

Full Companion Planting Guide for Napa Cabbage

See which plants help Napa Cabbage thrive, which to keep away, and raised bed layout tips →

🛠️ Supplies You'll Need

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🌾 Seed Saving Guide

🟡 Moderate
✅ Open-pollinated — seeds grow true to parent

When to Harvest Seed

Allow heads to bolt in spring heat. Harvest seed pods when tan and dry.

Processing

Thresh dried seed stalks, winnow to separate seeds.

Seed Viability

Up to 4 years when stored cool, dark, and dry.

Pro Tip

Brassica rapa — crosses with bok choy, turnip, and other rapa crops. Isolate by 300 feet.

🪴

Raised Bed Planting Guides

A 4×8 bed fits 14 plants of Napa Cabbage. See plant counts, spacing grids, and companion pairings for every bed size →

Frequently Asked Questions

When should I plant Napa Cabbage in Agate, North Dakota? +

In Agate (Zone 3b), start Napa Cabbage seeds indoors around Wednesday, April 8, 2026 and transplant outdoors around Wednesday, June 3, 2026.

What is the last frost date for Agate, North Dakota? +

The average last spring frost date for Agate, North Dakota (ZIP 58310) is around Wednesday, May 20, 2026. This is based on NOAA climate normals for USDA Zone 3b.

How long does Napa Cabbage take to grow? +

Napa Cabbage typically matures in about 70 days from transplanting. In Agate, that means you can expect harvest around Wednesday, June 3, 2026 plus 70 days.

Should I start Napa Cabbage indoors or direct sow in North Dakota? +

Napa Cabbage should be started indoors 6 weeks before your last frost date. In Agate, that means starting around Wednesday, April 8, 2026.

Other Plants for Agate

Growing Napa Cabbage in Zone 3b

Napa Cabbage (Brassica rapa subsp. pekinensis) is a popular garden vegetable. In Agate, North Dakota, which is in USDA Hardiness Zone 3b, you should start seeds indoors around Wednesday, April 8, 2026.

Your average last frost date is Wednesday, May 20, 2026. Plan to transplant your Napa Cabbage seedlings outdoors around Wednesday, June 3, 2026, about 2 weeks after your last frost date.