Blog

When to Plant Mizuna in Yuma County, AZ

Yuma County, Arizona Zone 10a May

Your May game plan for Yuma County, Arizona

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

Avg. last frost February 10
Avg. first frost December 1
Soil temp (4") 66°F
Watering Critical
Pest pressure High
Daylight 13.7 hrs

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.

Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.

At an elevation of 4,781 feet, Yuma County receives approximately 9.4 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. With low rainfall, drip irrigation is essential for growing Mizuna successfully. Mulch heavily to conserve soil moisture.

Yuma County, AZ (Zone 10a) Year-round
294 days
Last Spring Frost February 10
294 growing days
First Fall Frost December 1
Share this guide:

Yuma County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (233 days to spare)
Start indoors: Jan 6 Transplant: Feb 3 🍅 Harvest: Mar 10 – Apr 7
Recommended (50%) ✓ Fits season (231 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: Mar 17 – Apr 14
Safe Start (90%) ✓ Fits season (221 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: Apr 13 – May 11

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 Yuma County

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

Soil pH

Your soil pH (6.9–8.4) is more alkaline than Mizuna prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is low (0.8%). 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 8 weeks before your first frost date for a fall harvest.

Succession Planting Mizuna

12
successive plantings in your 294-day season

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

For a dedicated fall crop, sow by Oct 06.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.1″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,729 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — 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 0.6" 0" ❄️ Dormant
Feb 4.3" 0.5" 3.8" 🚿 Regular watering
Mar 4.3" 0.5" 3.8" 🚿 Regular watering
Apr 4.3" 0.3" 4" 🚿 Regular watering
May 4.3" 0.2" 4.1" 🚿 Regular watering
Jun 4.3" 0.3" 4" 🚿 Regular watering
Jul 4.3" 1.8" 2.5" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 4.3" 0.8" 3.5" 🚿 Regular watering
Nov 4.3" 0.5" 3.8" 🚿 Regular watering
Dec 4.3" 0.6" 3.7" 🚿 Regular watering

Water needs are for active growing months only (Feb–Dec in Yuma 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 5,605 GDD Excellent fit

Mizuna Planting Timeline — Yuma County, AZ

Mizuna Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 – Jan 27
Transplant Outdoors February 10 Feb 10 – Feb 24
Direct Sow January 20 Jan 20 – Feb 10
Harvest March 17 Mar 17 – Apr 14
Fall Sowing October 6 Oct 6 – Oct 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 2-3 times/week

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 10a

📆 Growing Season

294 days in Yuma County

Growing Tips for Mizuna in Yuma County

Direct sow Mizuna outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.

Sandy soil in Yuma 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 295.0-day season in Yuma 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.

Yuma County receives only 9" of rain annually. Mizuna needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Yuma County, AZ?

Yuma County is in Zone 10a with an average last frost of February 10. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Yuma County, AZ?

Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.

🌱

Your Yuma County Garden Planner — Free

A 24-page printable planner built for Yuma County (Zone 10a). 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 Yuma County, AZ. 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.