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When to Plant Mitsuba in Sitka City and Borough, AK

Sitka City and Borough, Alaska Zone 7b May

This month in Sitka City and Borough, Alaska

We've pulled the most time-sensitive tasks for Sitka City and Borough, Alaska this May and put them front and centre. Tackle them in order.

Avg. last frost April 20
Avg. first frost October 24
Soil temp (4") 64°F
Watering Critical
Pest pressure Moderate
Daylight 16.2 hrs
  1. Begin indoor sowing: mitsuba

    These need a head start before your last frost (April 20). Sow into cells now so you're ready to transplant in a few weeks.

June will be here before you know it — start on
  • 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.

Sitka City and Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 20 and the first fall frost is October 24, giving you a growing season of approximately 187 days.

At an elevation of 1,935 feet, Sitka City and Borough receives approximately 21.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 69°F, so choose short-season varieties of Mitsuba to ensure they mature before fall.

Sitka City and Borough, AK (Zone 7b) Moderate season
187 days
Last Spring Frost April 20
187 growing days
First Fall Frost October 24

Sitka City and Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (84 days to spare)
Start indoors: Mar 8 Transplant: Apr 5 🍅 Harvest: May 31 – Jul 26
Recommended (50%) ✓ Fits season (82 days to spare)
Start indoors: Mar 16 Transplant: Apr 13 🍅 Harvest: Jun 8 – Aug 3
Safe Start (90%) ✓ Fits season (76 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Jul 1 – Aug 26

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 Sitka City and Borough

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

Soil pH

Your soil pH (4.9–6.4) is more acidic than Mitsuba prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.5%) — 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

4
successive plantings in your 187-day season

Sow every 5.7 weeks. Last sowing by Aug 15 to harvest before frost.

For a dedicated fall crop, sow by Aug 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 849 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" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 0.7" 0" ❄️ Dormant
Apr 4.3" 0.6" 3.7" 🚿 Regular watering
May 4.3" 1.1" 3.2" 🚿 Regular watering
Jun 4.3" 1.5" 2.8" 🚿 Regular watering
Jul 4.3" 2.8" 1.5" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Sitka City and Borough). 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 ~105 GDD — county provides 327 GDD Excellent fit

Mitsuba Planting Timeline — Sitka City and Borough, AK

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 6 Apr 6 – Apr 27
Harvest June 8 Jun 8 – Aug 3
Fall Sowing August 15 Aug 15 – Aug 29

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

Month-by-Month Timeline

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

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 7b

📆 Growing Season

187 days in Sitka City and Borough

Growing Tips for Mitsuba in Sitka City and Borough

Direct sow Mitsuba outdoors after April 20 in Sitka City and Borough 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.

Sitka City and Borough receives only 22" 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 Sitka City and Borough, AK?

Sitka City and Borough is in Zone 7b with an average last frost of April 20. Plan your Mitsuba planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sitka City and Borough, AK?

Sitka City and Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 20 and first fall frost is October 24.

🌱

Your Sitka City and Borough Garden Planner — Free

A 24-page printable planner built for Sitka City and Borough (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Sitka City and Borough, AK. 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.