Blog

When to Plant Bok Choy in Norman County, MN

Norman County, Minnesota Zone 4a May

Your May planting checklist for Norman County, Minnesota

Here's what deserves your attention in Norman County, Minnesota this month. Everything below is tailored to Zone 4a and timed around your local frost dates.

Avg. last frost May 10
Avg. first frost October 1
Soil temp (4") 48°F
Watering Low
Pest pressure Low
Daylight 14.9 hrs
  1. Transplant bok choy outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Scatter bok choy into prepared beds

    These tolerate cool soil, so you're not gambling by sowing now.

To set up a strong June, finish these tasks
  • Starting indoors: bok choy
  • First harvests: bok choy

Instant PDF download. No spam, unsubscribe any time.

Bok choy is a Chinese cabbage variety with crisp white stalks and dark green leaves. It is a fast-growing cool-season crop ideal for stir-fries and soups.

Norman County, Minnesota is in USDA Zone 4a. 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 1,086 feet, Norman County receives approximately 38.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 78°F, so choose short-season varieties of Bok Choy to ensure they mature before fall.

Norman County, MN (Zone 4a) Short season
144 days
Last Spring Frost May 10
144 growing days
First Fall Frost October 1

Norman County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (71 days to spare)
Start indoors: Mar 21 Transplant: May 2 🍅 Harvest: Jun 13 – Jul 18
Recommended (50%) ✓ Fits season (67 days to spare)
Start indoors: Mar 29 Transplant: May 10 🍅 Harvest: Jun 21 – Jul 26
Safe Start (90%) ✓ Fits season (68 days to spare)
Start indoors: Apr 10 Transplant: May 22 🍅 Harvest: Jul 3 – Aug 7

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 Norman County

How your county's soil matches Bok Choy's growing requirements.

Soil pH

Your soil pH (5.9–6.9) overlaps with Bok Choy's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Norman County is excellent for Bok Choy — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Bok Choy is a heavy drinker but your soil drains very quickly. Mulch heavily and consider drip irrigation.

Organic Matter

Organic matter is excellent (4.0%) — Bok Choy will thrive.

How to Plant Bok Choy

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 Bok Choy

4
successive plantings in your 144-day season

Sow every 4.6 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Jul 09.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Bok Choy

Bok Choy needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Bok Choy Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 2.9" 0" ❄️ Dormant
Apr 3.3" 0" ❄️ Dormant
May 3" 4" 0" ✅ Rainfall sufficient
Jun 3" 4.5" 0" ✅ Rainfall sufficient
Jul 3" 3.8" 0" ✅ Rainfall sufficient
Aug 3" 4.8" 0" ✅ Rainfall sufficient
Sep 3" 3.5" 0" ✅ Rainfall sufficient
Oct 3" 3.3" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Norman County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Bok Choy 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.

Bok Choy needs ~425 GDD — county provides 1,224 GDD Excellent fit

Bok Choy Planting Timeline — Norman County, MN

Bok Choy 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 June 21 Jun 21 – Jul 26
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 Harvest
July Fall Sowing Harvest
August
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

144 days in Norman County

Growing Tips for Bok Choy in Norman County

Direct sow Bok Choy outdoors after May 10 in Norman County when soil has warmed and frost danger has passed.

Common pests for Bok Choy in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall for best results. Keep soil consistently moist. Harvest whole heads or cut outer leaves for a cut-and-come-again approach.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Bok Choy in Norman County, MN?

Norman County is in Zone 4a with an average last frost of May 10. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.

What planting zone is Norman County, MN?

Norman County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is October 1.

🌱

Your Norman County Garden Planner — Free

A 24-page printable planner built for Norman County (Zone 4a). 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 Norman County, MN. 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.