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When to Plant Mizuna in Pondera County, MT

Pondera County, Montana Zone 4a May

Your May planting checklist for Pondera County, Montana

We've pulled the most time-sensitive tasks for Pondera County, Montana this May and put them front and centre. Tackle them in order.

Avg. last frost May 23
Avg. first frost September 16
Soil temp (4") 28°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Set out mizuna seedlings

    Your last frost (May 23) has passed. These warm-season crops can handle outdoor soil now.

  2. Outdoor sowing time: mizuna

    These tolerate cool soil, so you're not gambling by sowing now.

June prep starts now
  • First harvests: mizuna
  • Fall sowing: 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.

Pondera County, Montana is in USDA Zone 4a. The average last spring frost is May 23 and the first fall frost is September 16, giving you a growing season of approximately 116 days.

At an elevation of 8,118 feet, Pondera County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Mizuna to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mizuna successfully. Mulch heavily to conserve soil moisture.

Pondera County, MT (Zone 4a) Short season
116 days
Last Spring Frost May 23
116 growing days
First Fall Frost September 16

Pondera County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (51 days to spare)
Start indoors: Apr 6 Transplant: May 18 🍅 Harvest: Jun 22 – Jul 20
Recommended (50%) ✓ Fits season (53 days to spare)
Start indoors: Apr 11 Transplant: May 23 🍅 Harvest: Jun 27 – Jul 25
Safe Start (90%) ✓ Fits season (47 days to spare)
Start indoors: Apr 28 Transplant: Jun 9 🍅 Harvest: Jul 14 – Aug 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 Pondera County

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

Soil pH

Your soil pH (6.6–8.3) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Mizuna.

How to Plant Mizuna

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 12 weeks before your first frost date for a fall harvest.

Succession Planting Mizuna

4
successive plantings in your 116-day season

Sow every 3.4 weeks. Last sowing by Aug 02 to harvest before frost.

For a dedicated fall crop, sow by Jun 24.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 414 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 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 1.9" 2.4" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 2" 2.3" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Pondera 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 ~431 GDD — county provides 1,334 GDD Excellent fit

Mizuna Planting Timeline — Pondera County, MT

Mizuna Planting Calendar

Activity When Date Range
Start Indoors April 11 Apr 11 – Apr 25
Transplant Outdoors May 23 May 23 – Jun 6
Direct Sow May 16 May 16 – Jun 6
Harvest June 27 Jun 27 – Jul 25
Fall Sowing June 24 Jun 24 – Jul 8

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

Month-by-Month Timeline

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

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: acceptable

🗺️ USDA Zone

Zone 4a

📆 Growing Season

116 days in Pondera County

Growing Tips for Mizuna in Pondera County

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

Your generous 116.0-day season in Pondera 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.

Pondera County receives only 18" 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 Pondera County, MT?

Pondera County is in Zone 4a 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 Pondera County, MT?

Pondera County, Montana is in USDA Hardiness Zone 4a. The average last spring frost is May 23 and first fall frost is September 16.

🌱

Your Pondera County Garden Planner — Free

A 24-page printable planner built for Pondera County (Zone 4a). 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 Pondera County, MT. 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.