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When to Plant Mitsuba in Mason County, MI

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.

Mason County, Michigan is in USDA Zone 5b. The average last spring frost is May 15 and the first fall frost is October 7, giving you a growing season of approximately 145 days.

At an elevation of 1,318 feet, Mason County receives approximately 34.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Mitsuba during the growing season.

Mason County, MI (Zone 5b) Short season
145 days
Last Spring Frost May 15
145 growing days
First Fall Frost October 7

Mason County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (41 days to spare)
Start indoors: Apr 3 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 21
Recommended (50%) ✓ Fits season (40 days to spare)
Start indoors: Apr 10 Transplant: May 8 🍅 Harvest: Jul 3 – Aug 28
Safe Start (90%) ✓ Fits season (42 days to spare)
Start indoors: Apr 24 Transplant: May 22 🍅 Harvest: Jul 17 – Sep 11

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 5 gal / 100 sq ft
Mitsuba needs ~825 GDD — county provides 1,993 GDD Excellent fit

Mitsuba Planting Timeline โ€” Mason County, MI

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors April 10 Apr 10 โ€“ Apr 24
Transplant Outdoors May 8 May 8 โ€“ May 22
Direct Sow May 1 May 1 โ€“ May 22
Fall Sowing July 29 Jul 29 โ€“ Aug 12
Harvest July 3 Jul 3 โ€“ Aug 28

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“70 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

145 days

Growing Tips for Mason County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Mitsuba in Mason County, MI?

Mason County is in Zone 5b with an average last frost of May 15. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Mason County, MI?

Mason County, Michigan is in USDA Hardiness Zone 5b. The average last spring frost is May 15 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Mason County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Mason County, MI. Local conditions may vary. Last updated: April 2026.