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When to Plant Mitsuba in Jefferson County, AR

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, Arkansas is in USDA Zone 7b. The average last spring frost is March 19 and the first fall frost is November 9, giving you a growing season of approximately 235 days.

At an elevation of 454 feet, Jefferson County receives approximately 51.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Mitsuba during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mitsuba root diseases.

Jefferson County, AR (Zone 7b) Long season
235 days
Last Spring Frost March 19
235 growing days
First Fall Frost November 9

Jefferson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (131 days to spare)
Start indoors: Feb 3 Transplant: Mar 3 🍅 Harvest: Apr 28 – Jun 23
Recommended (50%) ✓ Fits season (130 days to spare)
Start indoors: Feb 12 Transplant: Mar 12 🍅 Harvest: May 7 – Jul 2
Safe Start (90%) ✓ Fits season (128 days to spare)
Start indoors: Mar 4 Transplant: Apr 1 🍅 Harvest: May 27 – Jul 22

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 Jefferson County

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

Soil pH

Your soil pH (5.3โ€“7.1) overlaps with Mitsuba's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). 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

5
successive plantings in your 235-day season

Sow every 5.7 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Aug 31.

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 170 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€” 3.9" 0" โ„๏ธ Dormant
Mar 4.3" 5.4" 0" โœ… Rainfall sufficient
Apr 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 4.3" 0" โœ… Rainfall sufficient
Jul 4.3" 5.5" 0" โœ… Rainfall sufficient
Aug 4.3" 5.1" 0" โœ… Rainfall sufficient
Sep 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Oct 4.3" 3.7" 0.6" ๐Ÿ’ง Light watering
Nov 4.3" 4.4" 0" โœ… Rainfall sufficient
Dec โ€” 3.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Jefferson 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 ~1,005 GDD — county provides 3,936 GDD Excellent fit

Mitsuba Planting Timeline โ€” Jefferson County, AR

Mitsuba Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 โ€“ Feb 26
Transplant Outdoors March 12 Mar 12 โ€“ Mar 26
Direct Sow March 5 Mar 5 โ€“ Mar 26
Harvest May 7 May 7 โ€“ Jul 2
Fall Sowing August 31 Aug 31 โ€“ Sep 14

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Transplant Outdoors Direct Sow
April โ€”
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 7b

๐Ÿ“† Growing Season

235 days in Jefferson County

Growing Tips for Mitsuba in Jefferson County

Direct sow Mitsuba outdoors after March 19 in Jefferson 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 Jefferson County, AR?

Jefferson County is in Zone 7b with an average last frost of March 19. Plan your Mitsuba planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Jefferson County, AR?

Jefferson County, Arkansas is in USDA Hardiness Zone 7b. The average last spring frost is March 19 and first fall frost is November 9.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Jefferson County gardeners in Zone 7b 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 Jefferson County, AR. Local conditions may vary. Last updated: April 2026.