Blog

When to Plant Mizuna in Franklin County, KY

Franklin County, Kentucky Zone 6b May

Top priorities for Franklin County, Kentucky gardeners in May

A quick May briefing for Franklin County, Kentucky gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 11
Avg. first frost October 26
Soil temp (4") 55°F
Watering Moderate
Pest pressure Low
Daylight 14.1 hrs
  1. Begin indoor sowing: mizuna

    Your window is short. These crops want several weeks of indoor growth before they go outside.

  2. Start harvesting mizuna

    If you can't use it all right away, check the food-preservation section of your planner.

June will be here before you know it — start on
  • First harvests: mizuna

Instant PDF download. No spam, unsubscribe any time.

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.

Franklin County, Kentucky is in USDA Zone 6b. The average last spring frost is April 11 and the first fall frost is October 26, giving you a growing season of approximately 198 days.

At an elevation of 3,532 feet, Franklin County receives approximately 44.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Mizuna during the growing season.

Franklin County, KY (Zone 6b) Moderate season
198 days
Last Spring Frost April 11
198 growing days
First Fall Frost October 26

Franklin County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (132 days to spare)
Start indoors: Mar 3 Transplant: Apr 7 🍅 Harvest: May 12 – Jun 9
Recommended (50%) ✓ Fits season (135 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: May 16 – Jun 13
Safe Start (90%) ✓ Fits season (126 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jun 1 – Jun 29

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 Franklin County

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

Soil pH

Your soil pH (5.6–7.0) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.

Soil Texture

The silt loam soil in Franklin County is excellent for Mizuna — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.7%). 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

8
successive plantings in your 198-day season

Sow every 3.4 weeks. Last sowing by Sep 11 to harvest before frost.

For a dedicated fall crop, sow by Aug 17.

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 106 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 3.8" 0" ❄️ Dormant
Feb 3" 0" ❄️ Dormant
Mar 4.7" 0" ❄️ Dormant
Apr 4.3" 3.4" 0.9" 💧 Light watering
May 4.3" 3.5" 0.8" 💧 Light watering
Jun 4.3" 3.4" 0.9" 💧 Light watering
Jul 4.3" 4.7" 0" ✅ Rainfall sufficient
Aug 4.3" 4.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.5" 0.8" 💧 Light watering
Oct 4.3" 3.1" 1.2" 💧 Light watering
Nov 3.7" 0" ❄️ Dormant
Dec 3.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Franklin County). Supplement amounts are based on average rainfall — 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" — 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.

Mizuna needs ~600 GDD — county provides 3,168 GDD Excellent fit

Mizuna Planting Timeline — Franklin County, KY

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 7 Mar 7 – Mar 21
Transplant Outdoors April 11 Apr 11 – Apr 25
Direct Sow March 28 Mar 28 – Apr 18
Harvest May 16 May 16 – Jun 13
Fall Sowing August 17 Aug 17 – Aug 31

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

198 days in Franklin County

Growing Tips for Mizuna in Franklin County

Direct sow Mizuna outdoors after April 11 in Franklin County when soil has warmed and frost danger has passed.

Your generous 198.0-day season in Franklin 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 Franklin County, KY?

Franklin County is in Zone 6b with an average last frost of April 11. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Franklin County, KY?

Franklin County, Kentucky is in USDA Hardiness Zone 6b. The average last spring frost is April 11 and first fall frost is October 26.

🌱

Your Franklin County Garden Planner — Free

A 24-page printable planner built for Franklin County (Zone 6b). 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 Franklin County, KY. 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.