Blog

When to Plant Mitsuba in Kent County, DE

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.

Kent County, Delaware is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is November 4, giving you a growing season of approximately 216 days.

At an elevation of 128 feet, Kent County receives approximately 47.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Mitsuba during the growing season.

Kent County, DE (Zone 7a) Long season
216 days
Last Spring Frost April 2
216 growing days
First Fall Frost November 4

Kent County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Feb 21 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 11
Recommended (50%) ✓ Fits season (111 days to spare)
Start indoors: Feb 26 Transplant: Mar 26 🍅 Harvest: May 21 – Jul 16
Safe Start (90%) ✓ Fits season (106 days to spare)
Start indoors: Mar 14 Transplant: Apr 11 🍅 Harvest: Jun 6 – Aug 1

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 Kent County

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

Soil pH

Your soil pH (5.8โ€“6.8) overlaps with Mitsuba's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.2%). 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

5
successive plantings in your 216-day season

Sow every 5.7 weeks. Last sowing by Aug 26 to harvest before frost.

For a dedicated fall crop, sow by Aug 26.

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 132 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€” 4" 0" โ„๏ธ Dormant
Feb โ€” 2.9" 0" โ„๏ธ Dormant
Mar โ€” 3.5" 0" โ„๏ธ Dormant
Apr 4.3" 4" 0.3" ๐Ÿ’ง Light watering
May 4.3" 4.6" 0" โœ… Rainfall sufficient
Jun 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jul 4.3" 5.6" 0" โœ… Rainfall sufficient
Aug 4.3" 4.9" 0" โœ… Rainfall sufficient
Sep 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Oct 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Nov 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
Dec โ€” 3.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Kent 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 3,456 GDD Excellent fit

Mitsuba Planting Timeline โ€” Kent County, DE

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors February 26 Feb 26 โ€“ Mar 12
Transplant Outdoors March 26 Mar 26 โ€“ Apr 9
Direct Sow March 19 Mar 19 โ€“ Apr 9
Harvest May 21 May 21 โ€“ Jul 16
Fall Sowing August 26 Aug 26 โ€“ Sep 9

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

Month-by-Month Timeline

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

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

216 days in Kent County

Growing Tips for Mitsuba in Kent County

Direct sow Mitsuba outdoors after April 02 in Kent 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 Kent County, DE?

Kent County is in Zone 7a with an average last frost of April 2. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kent County, DE?

Kent County, Delaware is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is November 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kent County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Kent County, DE. Local conditions may vary. Last updated: April 2026.