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When to Plant Mizuna in Yuba County, CA

Yuba County, California Zone 9a April

Top priorities for Yuba County, California gardeners in April

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Yuba County, California.

Avg. last frost April 22
Avg. first frost November 9
Soil temp (4") 67°F
Watering High
Pest pressure High
Daylight 13 hrs
  1. Move mizuna into the garden

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Seed mizuna outdoors

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

Coming up in May — start thinking about
  • Starting indoors: mizuna
  • 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.

Yuba County, California is in USDA Zone 9a. The average last spring frost is April 22 and the first fall frost is November 9, giving you a growing season of approximately 201 days.

At an elevation of 303 feet, Yuba County receives approximately 26.5 inches of rainfall annually with predominantly loam soil. Summer highs average 94°F, providing good warmth for Mizuna during the growing season.

Yuba County, CA (Zone 9a) Long season
201 days
Last Spring Frost April 22
201 growing days
First Fall Frost November 9
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Yuba County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (137 days to spare)
Start indoors: Mar 17 Transplant: Apr 14 🍅 Harvest: May 19 – Jun 16
Recommended (50%) ✓ Fits season (138 days to spare)
Start indoors: Mar 25 Transplant: Apr 22 🍅 Harvest: May 27 – Jun 24
Safe Start (90%) ✓ Fits season (132 days to spare)
Start indoors: Apr 30 Transplant: May 28 🍅 Harvest: Jul 2 – Jul 30

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 Yuba County

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

Soil pH

Your soil pH (6.3–7.3) is within Mizuna's preferred range (6.0–7.5).

Soil Texture

The loam soil in Yuba County is excellent for Mizuna — 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 8 weeks before your first frost date for a fall harvest.

Succession Planting Mizuna

8
successive plantings in your 201-day season

Sow every 3.4 weeks. Last sowing by Sep 25 to harvest before frost.

For a dedicated fall crop, sow by Sep 14.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 958 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

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 4.9" 0" ❄️ Dormant
Feb 5.6" 0" ❄️ Dormant
Mar 4.6" 0" ❄️ Dormant
Apr 4.3" 2.2" 2.1" 💧 Light watering
May 4.3" 0.7" 3.6" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.3" 4" 🚿 Regular watering
Oct 4.3" 1.1" 3.2" 🚿 Regular watering
Nov 4.3" 2.8" 1.5" 💧 Light watering
Dec 4.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Nov in Yuba 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 ~769 GDD — county provides 4,120 GDD Excellent fit

Mizuna Planting Timeline — Yuba County, CA

Mizuna Planting Calendar

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors April 22 Apr 22 – May 6
Direct Sow April 1 Apr 1 – Apr 22
Harvest May 27 May 27 – Jun 24
Fall Sowing September 14 Sep 14 – Sep 28

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: ideal

🗺️ USDA Zone

Zone 9a

📆 Growing Season

201 days in Yuba County

Growing Tips for Mizuna in Yuba County

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

Your generous 201.0-day season in Yuba 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 Yuba County, CA?

Yuba County is in Zone 9a with an average last frost of April 22. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yuba County, CA?

Yuba County, California is in USDA Hardiness Zone 9a. The average last spring frost is April 22 and first fall frost is November 9.

🌱

Your Yuba County Garden Planner — Free

A 24-page printable planner built for Yuba County (Zone 9a). 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 Yuba County, CA. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.