When to Plant Mizuna in Door County, WI
May to-do list for Door County, Wisconsin
Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.
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Get mizuna in the ground
Harden off for 7 days — a little more sun each day — before planting. That's the difference between a seedling that thrives and one that stalls.
Looking ahead to June
- Starting indoors: mizuna
- First harvests: mizuna
Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.
Door County, Wisconsin is in USDA Zone 5b. The average last spring frost is May 11 and the first fall frost is October 8, giving you a growing season of approximately 150 days.
At an elevation of 564 feet, Door County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Mizuna during the growing season.
Door County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
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 Door County
How your county's soil matches Mizuna's growing requirements.
Soil pH
Your soil pH (6.0–7.3) is within Mizuna's preferred range (6.0–7.5).
Soil Texture
The silt loam soil in Door County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Mizuna.
Organic Matter
Organic matter is excellent (4.7%) — Mizuna will thrive.
How to Plant Mizuna
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Mizuna
Sow every 3.4 weeks. Last sowing by Aug 24 to harvest before frost.
For a dedicated fall crop, sow by Jul 30.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Mizuna
Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Mizuna Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.7" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | — | 3.4" | 0" | ❄️ Dormant |
| May | 4.3" | 4.6" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.7" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 4.7" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Oct | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Door County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Mizuna 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.
Mizuna Planting Timeline — Door County, WI
Mizuna Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 6 | Apr 6 – Apr 20 |
| Transplant Outdoors | May 11 | May 11 – May 25 |
| Direct Sow | April 27 | Apr 27 – May 18 |
| Harvest | June 15 | Jun 15 – Jul 13 |
| Fall Sowing | July 30 | Jul 30 – Aug 13 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| 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
1"/week · Only during dry spells
📅 Days to Maturity
30–45 days
🧪 Soil pH
Needs 6–7.5 · Your soil: ideal
🗺️ USDA Zone
Zone 5b
📆 Growing Season
150 days in Door County
Growing Tips for Mizuna in Door County
Direct sow Mizuna outdoors after May 11 in Door County when soil has warmed and frost danger has passed.
Your generous 150.0-day season in Door County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.
Common pests for Mizuna 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. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Mizuna in Other Locations
Frequently Asked Questions
When should I plant Mizuna in Door County, WI?
Door County is in Zone 5b with an average last frost of May 11. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.
What planting zone is Door County, WI?
Door County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is May 11 and first fall frost is October 8.
Your Door County Garden Planner — Free
A 24-page printable planner built for Door County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.