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When to Plant Mizuna in Northumberland County, VA

Northumberland County, Virginia Zone 8a May

Your May gardening checklist

Each item below is timed to Northumberland County, Virginia's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost April 5
Avg. first frost November 4
Soil temp (4") 68°F
Watering Low
Pest pressure Moderate
Daylight 14 hrs
  1. Indoor seed-starting week for mizuna

    These need a head start before your last frost (April 5). Sow into cells now so you're ready to transplant in a few weeks.

  2. Basket week: mizuna

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

June prep starts now
  • First harvests: mizuna

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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.

Northumberland County, Virginia is in USDA Zone 8a. The average last spring frost is April 5 and the first fall frost is November 4, giving you a growing season of approximately 213 days.

At an elevation of 207 feet, Northumberland County receives approximately 54.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Mizuna during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Mizuna root diseases.

Northumberland County, VA (Zone 8a) Long season
213 days
Last Spring Frost April 5
213 growing days
First Fall Frost November 4

Northumberland County Soil Profile

Soil Type

Silt Loam

Soil pH

5.4-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (153 days to spare)
Start indoors: Feb 21 Transplant: Mar 28 🍅 Harvest: May 2 – May 30
Recommended (50%) ✓ Fits season (150 days to spare)
Start indoors: Mar 1 Transplant: Apr 5 🍅 Harvest: May 10 – Jun 7
Safe Start (90%) ✓ Fits season (163 days to spare)
Start indoors: Mar 22 Transplant: Apr 26 🍅 Harvest: May 31 – Jun 28

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 Northumberland County

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

Soil pH

Your soil pH (5.4–7.1) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.5%). 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

8
successive plantings in your 213-day season

Sow every 3.4 weeks. Last sowing by Sep 20 to harvest before frost.

For a dedicated fall crop, sow by Aug 26.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.1″/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 4.4" 0" ❄️ Dormant
Feb 4.1" 0" ❄️ Dormant
Mar 5.2" 0" ❄️ Dormant
Apr 4.3" 4.2" 0.1" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 6.5" 0" ✅ Rainfall sufficient
Aug 4.3" 5.3" 0" ✅ Rainfall sufficient
Sep 4.3" 3.7" 0.6" 💧 Light watering
Oct 4.3" 4" 0.3" 💧 Light watering
Nov 4.3" 3.7" 0.6" 💧 Light watering
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Northumberland 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 4,047 GDD Excellent fit

Mizuna Planting Timeline — Northumberland County, VA

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors April 5 Apr 5 – Apr 19
Direct Sow March 22 Mar 22 – Apr 12
Harvest May 10 May 10 – Jun 7
Fall Sowing August 26 Aug 26 – Sep 9

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 Fall Sowing
October
November
December

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: acceptable

🗺️ USDA Zone

Zone 8a

📆 Growing Season

213 days in Northumberland County

Growing Tips for Mizuna in Northumberland County

Direct sow Mizuna outdoors after April 05 in Northumberland County when soil has warmed and frost danger has passed.

Your generous 213.0-day season in Northumberland 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 Northumberland County, VA?

Northumberland County is in Zone 8a with an average last frost of April 5. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Northumberland County, VA?

Northumberland County, Virginia is in USDA Hardiness Zone 8a. The average last spring frost is April 5 and first fall frost is November 4.

🌱

Your Northumberland County Garden Planner — Free

A 24-page printable planner built for Northumberland 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 Northumberland County, VA. 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.