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When to Plant Mitsuba in Jefferson County, OR

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.

Jefferson County, Oregon is in USDA Zone 6a. The average last spring frost is June 9 and the first fall frost is September 19, giving you a growing season of approximately 102 days.

At an elevation of 21 feet, Jefferson County receives approximately 36.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 79ยฐF, so choose short-season varieties of Mitsuba to ensure they mature before fall.

Jefferson County, OR (Zone 6a) Short season
102 days
Last Spring Frost June 9
102 growing days
First Fall Frost September 19

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.7

Drainage

Well Drained

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 โ€” 4.8" 0" โ„๏ธ Dormant
Feb โ€” 3.7" 0" โ„๏ธ Dormant
Mar โ€” 3.7" 0" โ„๏ธ Dormant
Apr โ€” 2.9" 0" โ„๏ธ Dormant
May โ€” 1.8" 0" โ„๏ธ Dormant
Jun 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Jul 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Aug 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering
Sep 4.3" 1.6" 2.7" ๐Ÿšฟ Regular watering
Oct โ€” 3.2" 0" โ„๏ธ Dormant
Nov โ€” 6.1" 0" โ„๏ธ Dormant
Dec โ€” 5.5" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Junโ€“Sep in Jefferson County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Mitsuba Planting Timeline โ€” Jefferson County, OR

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors May 5 May 5 โ€“ May 19
Transplant Outdoors June 2 Jun 2 โ€“ Jun 16
Direct Sow May 26 May 26 โ€“ Jun 16
Harvest July 28 Jul 28 โ€“ Sep 22
Fall Sowing July 11 Jul 11 โ€“ Jul 25

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6a

๐Ÿ“† Growing Season

102 days in Jefferson County

Growing Tips for Jefferson 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mitsuba in Jefferson County, OR?

Jefferson County is in Zone 6a with an average last frost of June 9. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, OR?

Jefferson County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 9 and first fall frost is September 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 6a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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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 Jefferson County, OR. Local conditions may vary. Last updated: April 2026.