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When to Plant Mizuna in Jefferson County, AR

Mizuna is a mild-flavored Japanese mustard green with feathery, deeply serrated leaves. It is fast-growing and makes an excellent addition to salads and stir-fries.

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 Mizuna during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mizuna 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 (173 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: Apr 14 – May 12
Recommended (50%) ✓ Fits season (172 days to spare)
Start indoors: Feb 12 Transplant: Mar 19 🍅 Harvest: Apr 23 – May 21
Safe Start (90%) ✓ Fits season (170 days to spare)
Start indoors: Mar 4 Transplant: Apr 8 🍅 Harvest: May 13 – Jun 10

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 Mizuna's growing requirements.

Soil pH

Your soil pH (5.3โ€“7.1) overlaps with Mizuna's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.5%). Annual compost additions will help Mizuna.

How to Plant Mizuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Mizuna

9
successive plantings in your 235-day season

Sow every 3.4 weeks. Last sowing by Sep 25 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 Mizuna

Mizuna needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mizuna 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.

Mizuna 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.

Mizuna needs ~628 GDD — county provides 3,936 GDD Excellent fit

Mizuna Planting Timeline โ€” Jefferson County, AR

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 โ€“ Feb 26
Transplant Outdoors March 19 Mar 19 โ€“ Apr 2
Direct Sow March 5 Mar 5 โ€“ Mar 26
Harvest April 23 Apr 23 โ€“ May 21
Fall Sowing August 31 Aug 31 โ€“ Sep 14

Plant 0.5" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Transplant Outdoors Direct Sow
April Transplant Outdoors Harvest
May Harvest
June โ€”
July โ€”
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

30โ€“45 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

235 days in Jefferson County

Growing Tips for Mizuna in Jefferson County

Direct sow Mizuna outdoors after March 19 in Jefferson County when soil has warmed and frost danger has passed.

Your generous 235.0-day season in Jefferson County allows multiple plantings of Mizuna. Sow every 15.0 days for continuous harvest.

Common pests for Mizuna in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring or fall. Harvest outer leaves as needed for a cut-and-come-again approach. Mizuna is one of the most cold-tolerant Asian greens.

Companion Planting

Good Companions

Avoid Planting Near

  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mizuna in Jefferson County, AR?

Jefferson County is in Zone 7b with an average last frost of March 19. Plan your Mizuna 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.