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When to Plant Mitsuba in Baker County, OR

Baker County, Oregon Zone 6b May

Your May gardening checklist

May is a pivotal month for Baker County, Oregon gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 30
Avg. first frost September 12
Soil temp (4") 58°F
Watering Critical
Pest pressure Low
Daylight 14.6 hrs
  1. Move mitsuba into the garden

    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.

  2. Direct-sow mitsuba

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

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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.

Baker County, Oregon is in USDA Zone 6b. The average last spring frost is May 30 and the first fall frost is September 12, giving you a growing season of approximately 105 days.

At an elevation of 1,398 feet, Baker County receives approximately 16.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Mitsuba during the growing season. With low rainfall, drip irrigation is essential for growing Mitsuba successfully. Mulch heavily to conserve soil moisture.

Baker County, OR (Zone 6b) Short season
105 days
Last Spring Frost May 30
105 growing days
First Fall Frost September 12
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Baker County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (5 days to spare)
Start indoors: Apr 14 Transplant: May 12 🍅 Harvest: Jul 7 – Sep 1
Recommended (50%) ✓ Fits season (0 days to spare)
Start indoors: Apr 25 Transplant: May 23 🍅 Harvest: Jul 18 – Sep 12
Safe Start (90%) ✓ Fits season (0 days to spare)
Start indoors: May 15 Transplant: Jun 12 🍅 Harvest: Aug 7 – Oct 2

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 Baker County

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

Soil pH

Your soil pH (5.3–6.5) is more acidic than Mitsuba prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Mitsuba.

Organic Matter

Organic matter is excellent (4.8%) — 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

2
successive plantings in your 105-day season

Sow every 5.7 weeks. Last sowing by Jul 04 to harvest before frost.

For a dedicated fall crop, sow by Jul 04.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 583 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 2.3" 0" ❄️ Dormant
Feb 1.7" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 1.1" 0" ❄️ Dormant
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.3" 4" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 2.5" 0" ❄️ Dormant
Dec 3.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Baker 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 ~870 GDD — county provides 1,522 GDD Excellent fit

Mitsuba Planting Timeline — Baker County, OR

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors April 25 Apr 25 – May 9
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest July 18 Jul 18 – Sep 12
Fall Sowing July 4 Jul 4 – Jul 18

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 6b

📆 Growing Season

105 days in Baker County

Growing Tips for Mitsuba in Baker County

Direct sow Mitsuba outdoors after May 30 in Baker 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.

Baker County receives only 17" of rain annually. Mitsuba needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Baker County, OR?

Baker County is in Zone 6b with an average last frost of May 30. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.

What planting zone is Baker County, OR?

Baker County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is May 30 and first fall frost is September 12.

🌱

Your Baker County Garden Planner — Free

A 24-page printable planner built for Baker County (Zone 6b). 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 Baker County, OR. 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.