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When to Plant Mitsuba in Winnebago County, WI

Winnebago County, Wisconsin Zone 5b May

This month in Winnebago County, Wisconsin

Your Winnebago County, Wisconsin garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost April 30
Avg. first frost October 12
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
Before June arrives, get these ready
  • Starting indoors: mitsuba
  • First harvests: mitsuba

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Mitsuba (Japanese parsley) is a shade-loving herb with trefoil leaves and a mild celery-parsley flavor. It is essential in Japanese cuisine for soups, salads, and garnishes.

Winnebago County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 30 and the first fall frost is October 12, giving you a growing season of approximately 165 days.

At an elevation of 608 feet, Winnebago County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Mitsuba to ensure they mature before fall.

Winnebago County, WI (Zone 5b) Moderate season
165 days
Last Spring Frost April 30
165 growing days
First Fall Frost October 12

Winnebago 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 (58 days to spare)
Start indoors: Mar 21 Transplant: Apr 18 🍅 Harvest: Jun 13 – Aug 8
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Mar 26 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 13
Safe Start (90%) ✓ Fits season (60 days to spare)
Start indoors: Apr 10 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 28

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 Winnebago County

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

Soil pH

Your soil pH (6.3–6.7) is within Mitsuba's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.7%) — Mitsuba will thrive.

How to Plant Mitsuba

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mitsuba

3
successive plantings in your 165-day season

Sow every 5.7 weeks. Last sowing by Aug 03 to harvest before frost.

For a dedicated fall crop, sow by Aug 03.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 26 gal / 100 sq ft

Monthly Watering Guide for Mitsuba

Mitsuba needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mitsuba Needs Rainfall You Supplement Action
Jan 1.8" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.8" 0" ❄️ Dormant
Apr 4.3" 3.7" 0.6" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.3" 0" ✅ Rainfall sufficient
Jul 4.3" 4.4" 0" ✅ Rainfall sufficient
Aug 4.3" 4.5" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.8" 1.5" 💧 Light watering
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

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

Mitsuba 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.

Mitsuba needs ~690 GDD — county provides 1,897 GDD Excellent fit

Mitsuba Planting Timeline — Winnebago County, WI

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors March 26 Mar 26 – Apr 9
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 16 Apr 16 – May 7
Harvest June 18 Jun 18 – Aug 13
Fall Sowing August 3 Aug 3 – Aug 17

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Fall Sowing Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 5b

📆 Growing Season

165 days in Winnebago County

Growing Tips for Mitsuba in Winnebago County

Direct sow Mitsuba outdoors after April 30 in Winnebago County when soil has warmed and frost danger has passed.

Common pests for Mitsuba in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow or start indoors in partial shade. Mitsuba prefers cool, moist conditions. Harvest outer stems as needed. Self-sows readily in shaded garden areas.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mitsuba in Winnebago County, WI?

Winnebago County is in Zone 5b with an average last frost of April 30. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winnebago County, WI?

Winnebago County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 30 and first fall frost is October 12.

🌱

Your Winnebago County Garden Planner — Free

A 24-page printable planner built for Winnebago 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.

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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 Winnebago County, WI. 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.