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When to Plant Mizuna in Goodhue County, MN

Goodhue County, Minnesota Zone 4b May

May to-do list for Goodhue County, Minnesota

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

Avg. last frost April 27
Avg. first frost October 8
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
June prep starts now
  • Starting indoors: mizuna
  • First harvests: mizuna

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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.

Goodhue County, Minnesota is in USDA Zone 4b. The average last spring frost is April 27 and the first fall frost is October 8, giving you a growing season of approximately 164 days.

At an elevation of 1,136 feet, Goodhue County receives approximately 34 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mizuna to ensure they mature before fall.

Goodhue County, MN (Zone 4b) Moderate season
164 days
Last Spring Frost April 27
164 growing days
First Fall Frost October 8

Goodhue County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (100 days to spare)
Start indoors: Mar 11 Transplant: Apr 22 🍅 Harvest: May 27 – Jun 24
Recommended (50%) ✓ Fits season (101 days to spare)
Start indoors: Mar 16 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jun 29
Safe Start (90%) ✓ Fits season (98 days to spare)
Start indoors: Apr 4 Transplant: May 16 🍅 Harvest: Jun 20 – Jul 18

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 Goodhue County

How your county's soil matches Mizuna's growing requirements.

Soil pH

Your soil pH (6.3–6.7) is within Mizuna's preferred range (6.0–7.5).

Soil Texture

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

Organic Matter

Organic matter is moderate (3.9%). Annual compost additions will help Mizuna.

How to Plant Mizuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Mizuna

6
successive plantings in your 164-day season

Sow every 3.4 weeks. Last sowing by Aug 24 to harvest before frost.

For a dedicated fall crop, sow by Jul 16.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 189 gal / 100 sq ft

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 1.6" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 4.3" 3.1" 1.2" 💧 Light watering
May 4.3" 4" 0.3" 💧 Light watering
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.5" 0.8" 💧 Light watering
Sep 4.3" 3" 1.3" 💧 Light watering
Oct 4.3" 2.6" 1.7" 💧 Light watering
Nov 2.7" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Goodhue 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 needs ~459 GDD — county provides 2,009 GDD Excellent fit

Mizuna Planting Timeline — Goodhue County, MN

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 27 Apr 27 – May 11
Direct Sow April 20 Apr 20 – May 11
Harvest June 1 Jun 1 – Jun 29
Fall Sowing July 16 Jul 16 – Jul 30

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Fall Sowing
August
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 4b

📆 Growing Season

164 days in Goodhue County

Growing Tips for Mizuna in Goodhue County

Direct sow Mizuna outdoors after April 27 in Goodhue County when soil has warmed and frost danger has passed.

Your generous 164.0-day season in Goodhue 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

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Goodhue County, MN?

Goodhue County is in Zone 4b with an average last frost of April 27. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Goodhue County, MN?

Goodhue County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 27 and first fall frost is October 8.

🌱

Your Goodhue County Garden Planner — Free

A 24-page printable planner built for Goodhue 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.

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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 Goodhue 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.