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When to Plant Mitsuba in Bucks County, PA

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.

Bucks County, Pennsylvania is in USDA Zone 6b. The average last spring frost is April 18 and the first fall frost is October 25, giving you a growing season of approximately 190 days.

At an elevation of 958 feet, Bucks County receives approximately 42.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Mitsuba during the growing season.

Bucks County, PA (Zone 6b) Moderate season
190 days
Last Spring Frost April 18
190 growing days
First Fall Frost October 25

Bucks County Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (83 days to spare)
Start indoors: Mar 9 Transplant: Apr 6 🍅 Harvest: Jun 1 – Jul 27
Recommended (50%) ✓ Fits season (85 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: Jun 6 – Aug 1
Safe Start (90%) ✓ Fits season (72 days to spare)
Start indoors: Apr 6 Transplant: May 4 🍅 Harvest: Jun 29 – Aug 24

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 Bucks County

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

Soil pH

Your soil pH (5.0โ€“6.6) is more acidic than Mitsuba prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Bucks County is excellent for Mitsuba โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.5%). Annual compost additions will help Mitsuba.

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 190-day season

Sow every 5.7 weeks. Last sowing by Aug 16 to harvest before frost.

For a dedicated fall crop, sow by Aug 16.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 95 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 โ€” 3.1" 0" โ„๏ธ Dormant
Feb โ€” 2.8" 0" โ„๏ธ Dormant
Mar โ€” 3.8" 0" โ„๏ธ Dormant
Apr 4.3" 3.3" 1" ๐Ÿ’ง Light watering
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Jul 4.3" 4.8" 0" โœ… Rainfall sufficient
Aug 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Sep 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Oct 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Nov โ€” 2.8" 0" โ„๏ธ Dormant
Dec โ€” 3.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Bucks County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~960 GDD — county provides 3,040 GDD Excellent fit

Mitsuba Planting Timeline โ€” Bucks County, PA

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 โ€“ Mar 28
Transplant Outdoors April 11 Apr 11 โ€“ Apr 25
Direct Sow April 4 Apr 4 โ€“ Apr 25
Harvest June 6 Jun 6 โ€“ Aug 1
Fall Sowing August 16 Aug 16 โ€“ Aug 30

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

50โ€“70 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

190 days in Bucks County

Growing Tips for Mitsuba in Bucks County

Direct sow Mitsuba outdoors after April 18 in Bucks 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 Bucks County, PA?

Bucks County is in Zone 6b with an average last frost of April 18. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bucks County, PA?

Bucks County, Pennsylvania is in USDA Hardiness Zone 6b. The average last spring frost is April 18 and first fall frost is October 25.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bucks County gardeners in Zone 6b 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 Bucks County, PA. Local conditions may vary. Last updated: April 2026.