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When to Plant Mizuna in Wheeler County, OR

Wheeler County, Oregon Zone 7a May

May in the garden — Wheeler County, Oregon

Your garden in Wheeler County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 23
Avg. first frost September 23
Soil temp (4") 55°F
Watering High
Pest pressure Low
Daylight 14.6 hrs
  1. Harden off and plant mizuna

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

  2. Sow mizuna where they'll grow

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

June prep starts now
  • 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.

Wheeler County, Oregon is in USDA Zone 7a. The average last spring frost is May 23 and the first fall frost is September 23, giving you a growing season of approximately 123 days.

At an elevation of 2,175 feet, Wheeler County receives approximately 22.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Mizuna to ensure they mature before fall.

Wheeler County, OR (Zone 7a) Short season
123 days
Last Spring Frost May 23
123 growing days
First Fall Frost September 23
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Wheeler County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (54 days to spare)
Start indoors: Apr 11 Transplant: May 16 🍅 Harvest: Jun 20 – Jul 18
Recommended (50%) ✓ Fits season (60 days to spare)
Start indoors: Apr 18 Transplant: May 23 🍅 Harvest: Jun 27 – Jul 25
Safe Start (90%) ✓ Fits season (62 days to spare)
Start indoors: May 15 Transplant: Jun 19 🍅 Harvest: Jul 24 – Aug 21

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 Wheeler County

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

Soil pH

Your soil pH (5.2–6.3) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (5.7%) — Mizuna will thrive.

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

4
successive plantings in your 123-day season

Sow every 3.4 weeks. Last sowing by Aug 09 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 242 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" 0" ❄️ Dormant
Feb 2.3" 0" ❄️ Dormant
Mar 2.6" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 4.3" 1.5" 2.8" 🚿 Regular watering
Jun 4.3" 1" 3.3" 🚿 Regular watering
Jul 4.3" 0.4" 3.9" 🚿 Regular watering
Aug 4.3" 0.4" 3.9" 🚿 Regular watering
Sep 4.3" 0.8" 3.5" 🚿 Regular watering
Oct 2.1" 0" ❄️ Dormant
Nov 3.3" 0" ❄️ Dormant
Dec 3.8" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wheeler 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 ~459 GDD — county provides 1,506 GDD Excellent fit

Mizuna Planting Timeline — Wheeler County, OR

Mizuna Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 – May 2
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 9 May 9 – May 30
Harvest June 27 Jun 27 – Jul 25
Fall Sowing July 15 Jul 15 – Jul 29

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 7a

📆 Growing Season

123 days in Wheeler County

Growing Tips for Mizuna in Wheeler County

Direct sow Mizuna outdoors after May 23 in Wheeler County when soil has warmed and frost danger has passed.

Your generous 123.0-day season in Wheeler 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.

Wheeler County receives only 23" 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 Wheeler County, OR?

Wheeler County is in Zone 7a with an average last frost of May 23. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wheeler County, OR?

Wheeler County, Oregon is in USDA Hardiness Zone 7a. The average last spring frost is May 23 and first fall frost is September 23.

🌱

Your Wheeler County Garden Planner — Free

A 24-page printable planner built for Wheeler County (Zone 7a). 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 Wheeler County, OR. 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.