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When to Plant Mizuna in Williamsburg County, SC

Williamsburg County, South Carolina Zone 8b May

Your May gardening checklist

May is a pivotal month for Williamsburg County, South Carolina gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 22
Avg. first frost November 13
Soil temp (4") 72°F
Watering Low
Pest pressure High
Daylight 13.7 hrs
  1. Bring in the mizuna

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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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.

Williamsburg County, South Carolina is in USDA Zone 8b. The average last spring frost is March 22 and the first fall frost is November 13, giving you a growing season of approximately 236 days.

At an elevation of 139 feet, Williamsburg County receives approximately 52.7 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92°F, providing good warmth for Mizuna during the growing season. Sandy soil warms quickly in spring — great for early planting — but Mizuna will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mizuna root diseases.

Williamsburg County, SC (Zone 8b) Long season
236 days
Last Spring Frost March 22
236 growing days
First Fall Frost November 13
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Williamsburg County Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (175 days to spare)
Start indoors: Feb 3 Transplant: Mar 10 🍅 Harvest: Apr 14 – May 12
Recommended (50%) ✓ Fits season (173 days to spare)
Start indoors: Feb 15 Transplant: Mar 22 🍅 Harvest: Apr 26 – May 24
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 Williamsburg County

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

Soil pH

Your soil pH (5.0–6.4) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

Sandy soil in Williamsburg County warms quickly in spring but drains fast. Mizuna will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Mizuna.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting 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 236-day season

Sow every 3.4 weeks. Last sowing by Sep 29 to harvest before frost.

For a dedicated fall crop, sow by Sep 04.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.2" 0" ❄️ Dormant
Feb 4.5" 0" ❄️ Dormant
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 4.5" 0" ✅ Rainfall sufficient
May 4.3" 4.1" 0.2" 💧 Light watering
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 5.9" 0" ✅ Rainfall sufficient
Aug 4.3" 5.2" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 4.3" 4.3" 0" ✅ Rainfall sufficient
Dec 4.4" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Williamsburg 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 ~712 GDD — county provides 4,484 GDD Excellent fit

Mizuna Planting Timeline — Williamsburg County, SC

Mizuna Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors March 22 Mar 22 – Apr 5
Direct Sow March 8 Mar 8 – Mar 29
Harvest April 26 Apr 26 – May 24
Fall Sowing September 4 Sep 4 – Sep 18

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 Harvest
May Harvest
June
July
August
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

236 days in Williamsburg County

Growing Tips for Mizuna in Williamsburg County

Direct sow Mizuna outdoors after March 22 in Williamsburg County when soil has warmed and frost danger has passed.

Sandy soil in Williamsburg County dries quickly — mulch Mizuna with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your generous 236.0-day season in Williamsburg 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 Williamsburg County, SC?

Williamsburg County is in Zone 8b with an average last frost of March 22. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Williamsburg County, SC?

Williamsburg County, South Carolina is in USDA Hardiness Zone 8b. The average last spring frost is March 22 and first fall frost is November 13.

🌱

Your Williamsburg County Garden Planner — Free

A 24-page printable planner built for Williamsburg County (Zone 8b). 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 Williamsburg County, SC. 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.