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When to Plant Bok Choy in Bay County, MI

Bay County, Michigan Zone 6a May

May to-do list for Bay County, Michigan

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

Avg. last frost May 10
Avg. first frost October 7
Soil temp (4") 59°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Move bok choy from tray to bed

    Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.

Looking ahead to June
  • Starting indoors: bok choy
  • First harvests: bok choy

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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.

Bay County, Michigan is in USDA Zone 6a. The average last spring frost is May 10 and the first fall frost is October 7, giving you a growing season of approximately 150 days.

At an elevation of 835 feet, Bay County receives approximately 33 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Bok Choy during the growing season.

Bay County, MI (Zone 6a) Moderate season
150 days
Last Spring Frost May 10
150 growing days
First Fall Frost October 7

Bay County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Mar 27 Transplant: May 1 🍅 Harvest: Jun 12 – Jul 17
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Apr 5 Transplant: May 10 🍅 Harvest: Jun 21 – Jul 26
Safe Start (90%) ✓ Fits season (75 days to spare)
Start indoors: Apr 17 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 Bay County

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

Soil pH

Your soil pH (6.1–6.8) is within Bok Choy's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) — Bok Choy will thrive.

How to Plant Bok Choy

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 Bok Choy

4
successive plantings in your 150-day season

Sow every 4.6 weeks. Last sowing by Aug 08 to harvest before frost.

For a dedicated fall crop, sow by Jul 29.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.9″/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 1.4" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 3" 3.8" 0" ✅ Rainfall sufficient
Jun 3" 4.5" 0" ✅ Rainfall sufficient
Jul 3" 3.5" 0" ✅ Rainfall sufficient
Aug 3" 3.7" 0" ✅ Rainfall sufficient
Sep 3" 2.9" 0.1" 💧 Light watering
Oct 3" 2.3" 0.7" 💧 Light watering
Nov 2" 0" ❄️ Dormant
Dec 1.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Bay 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 ~762 GDD — county provides 2,287 GDD Excellent fit

Bok Choy Planting Timeline — Bay County, MI

Bok Choy Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 10 May 10 – May 24
Direct Sow April 26 Apr 26 – May 17
Harvest June 21 Jun 21 – Jul 26
Fall Sowing July 29 Jul 29 – Aug 12

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

Month-by-Month Timeline

MonthActivities
January
February
March
April Start Indoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing Harvest
August Fall Sowing
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: ideal

🗺️ USDA Zone

Zone 6a

📆 Growing Season

150 days in Bay County

Growing Tips for Bok Choy in Bay County

Direct sow Bok Choy outdoors after May 10 in Bay 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 Bay County, MI?

Bay County is in Zone 6a 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 Bay County, MI?

Bay County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is May 10 and first fall frost is October 7.

🌱

Your Bay County Garden Planner — Free

A 24-page printable planner built for Bay County (Zone 6a). 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 Bay County, MI. 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.