When to Plant Bok Choy in Dunn County, WI
Top priorities for Dunn County, Wisconsin gardeners in May
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.
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Harden off and plant bok choy
Frost risk is low now in Dunn County, Wisconsin. If you've been covering beds overnight, you can stop.
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Scatter bok choy into prepared beds
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
A few tasks this May that'll pay off in June
- Starting indoors: bok choy
- First harvests: bok choy
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.
Dunn County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 12 and the first fall frost is September 29, giving you a growing season of approximately 140 days.
At an elevation of 1,221 feet, Dunn County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 81°F, so choose short-season varieties of Bok Choy to ensure they mature before fall.
Dunn County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
Drainage
Well Drained
Plant Planting Risk Windows
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 Dunn County
How your county's soil matches Bok Choy's growing requirements.
Soil pH
Your soil pH (5.9–6.7) overlaps with Bok Choy's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Dunn County is excellent for Bok Choy — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (4.0%). Annual compost additions will help Bok Choy.
How to Plant Bok Choy
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Bok Choy
Sow every 4.6 weeks. Last sowing by Jul 31 to harvest before frost.
For a dedicated fall crop, sow by Jul 07.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 2.1" | 0" | ❄️ Dormant |
| Apr | — | 3.2" | 0" | ❄️ Dormant |
| May | 3" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 3" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 3" | 4" | 0" | ✅ Rainfall sufficient |
| Aug | 3" | 4.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3" | 2.7" | 0.3" | 💧 Light watering |
| Oct | — | 2.8" | 0" | ❄️ Dormant |
| Nov | — | 2.8" | 0" | ❄️ Dormant |
| Dec | — | 1.8" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Dunn 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 Planting Timeline — Dunn County, WI
Bok Choy Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 31 | Mar 31 – Apr 14 |
| Transplant Outdoors | May 12 | May 12 – May 26 |
| Direct Sow | May 5 | May 5 – May 26 |
| Harvest | June 23 | Jun 23 – Jul 28 |
| Fall Sowing | July 7 | Jul 7 – Jul 21 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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 4b
📆 Growing Season
140 days in Dunn County
Growing Tips for Bok Choy in Dunn County
Direct sow Bok Choy outdoors after May 12 in Dunn 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
Check more plant combinations with our Companion Planting Checker →
Bok Choy in Other Locations
Frequently Asked Questions
When should I plant Bok Choy in Dunn County, WI?
Dunn County is in Zone 4b with an average last frost of May 12. Plan your Bok Choy planting based on this frost date — see the calendar above for exact timing.
What planting zone is Dunn County, WI?
Dunn County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 12 and first fall frost is September 29.
Your Dunn County Garden Planner — Free
A 24-page printable planner built for Dunn 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.