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When to Plant Mizuna in St. Clair County, AL

St. Clair County, Alabama Zone 8a May

This month in St. Clair County, Alabama

Your St. Clair County, Alabama garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

Avg. last frost March 27
Avg. first frost November 1
Soil temp (4") 67°F
Watering Moderate
Pest pressure Moderate
Daylight 13.7 hrs
  1. Get mizuna seeds going inside

    These need a head start before your last frost (March 27). Sow into cells now so you're ready to transplant in a few weeks.

  2. Pick mizuna

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

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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.

St. Clair County, Alabama is in USDA Zone 8a. The average last spring frost is March 27 and the first fall frost is November 1, giving you a growing season of approximately 219 days.

At an elevation of 211 feet, St. Clair County receives approximately 48.4 inches of rainfall annually with predominantly clay loam soil. Summer highs average 89°F, providing good warmth for Mizuna during the growing season. Clay soil retains moisture well for Mizuna, but amend with compost to improve drainage and prevent root rot.

St. Clair County, AL (Zone 8a) Long season
219 days
Last Spring Frost March 27
219 growing days
First Fall Frost November 1

St. Clair County Soil Profile

Soil Type

Clay Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (159 days to spare)
Start indoors: Feb 13 Transplant: Mar 20 🍅 Harvest: Apr 24 – May 22
Recommended (50%) ✓ Fits season (156 days to spare)
Start indoors: Feb 20 Transplant: Mar 27 🍅 Harvest: May 1 – May 29
Safe Start (90%) ✓ Fits season (152 days to spare)
Start indoors: Mar 11 Transplant: Apr 15 🍅 Harvest: May 20 – Jun 17

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 St. Clair County

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

Soil pH

Your soil pH (5.3–6.8) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.

Soil Texture

The clay loam soil in St. Clair 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 219-day season

Sow every 3.4 weeks. Last sowing by Sep 17 to harvest before frost.

For a dedicated fall crop, sow by Aug 23.

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 140 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 3.9" 0" ❄️ Dormant
Feb 3.6" 0" ❄️ Dormant
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 3.8" 0.5" 💧 Light watering
May 4.3" 3.7" 0.6" 💧 Light watering
Jun 4.3" 4.8" 0" ✅ Rainfall sufficient
Jul 4.3" 4.8" 0" ✅ Rainfall sufficient
Aug 4.3" 4.4" 0" ✅ Rainfall sufficient
Sep 4.3" 4.3" 0" ✅ Rainfall sufficient
Oct 4.3" 3.6" 0.7" 💧 Light watering
Nov 4.3" 3.4" 0.9" 💧 Light watering
Dec 3.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in St. Clair 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 ~628 GDD — county provides 3,668 GDD Excellent fit

Mizuna Planting Timeline — St. Clair County, AL

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 20 Feb 20 – Mar 6
Transplant Outdoors March 27 Mar 27 – Apr 10
Direct Sow March 13 Mar 13 – Apr 3
Harvest May 1 May 1 – May 29
Fall Sowing August 23 Aug 23 – Sep 6

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

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors Transplant Outdoors Direct Sow
April Transplant Outdoors Direct Sow
May Harvest
June
July
August Fall Sowing
September Fall Sowing
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 8a

📆 Growing Season

219 days in St. Clair County

Growing Tips for Mizuna in St. Clair County

Direct sow Mizuna outdoors after March 27 in St. Clair County when soil has warmed and frost danger has passed.

With St. Clair County's clay soil (26% clay), work in 3-4 inches of compost before planting Mizuna. Avoid tilling when soil is wet to prevent compaction.

Your generous 219.0-day season in St. Clair 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 St. Clair County, AL?

St. Clair County is in Zone 8a with an average last frost of March 27. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is St. Clair County, AL?

St. Clair County, Alabama is in USDA Hardiness Zone 8a. The average last spring frost is March 27 and first fall frost is November 1.

🌱

Your St. Clair County Garden Planner — Free

A 24-page printable planner built for St. Clair County (Zone 8a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 St. Clair County, AL. 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.