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When to Plant Mizuna in Sheridan County, MT

Sheridan County, Montana Zone 3b May

What to do in May

Here's what deserves your attention in Sheridan County, Montana this month. Everything below is tailored to Zone 3b and timed around your local frost dates.

Avg. last frost May 17
Avg. first frost September 18
Soil temp (4") 26°F
Watering High
Pest pressure Low
Daylight 15 hrs
  1. Move mizuna from tray to bed

    Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.

  2. Seed mizuna outdoors

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

Looking ahead to June
  • Starting indoors: mizuna
  • 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.

Sheridan County, Montana is in USDA Zone 3b. The average last spring frost is May 17 and the first fall frost is September 18, giving you a growing season of approximately 124 days.

At an elevation of 8,209 feet, Sheridan County receives approximately 16.8 inches of rainfall annually with predominantly loam soil. Summer highs average 79°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.

Sheridan County, MT (Zone 3b) Short season
124 days
Last Spring Frost May 17
124 growing days
First Fall Frost September 18
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Sheridan County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (60 days to spare)
Start indoors: Apr 1 Transplant: May 13 🍅 Harvest: Jun 17 – Jul 15
Recommended (50%) ✓ Fits season (61 days to spare)
Start indoors: Apr 5 Transplant: May 17 🍅 Harvest: Jun 21 – Jul 19
Safe Start (90%) ✓ Fits season (56 days to spare)
Start indoors: Apr 22 Transplant: Jun 3 🍅 Harvest: Jul 8 – Aug 5

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 Sheridan County

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

Soil pH

Your soil pH (6.3–7.9) overlaps with Mizuna's range (6.0–7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.6%). 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 124-day season

Sow every 3.4 weeks. Last sowing by Aug 04 to harvest before frost.

For a dedicated fall crop, sow by Jun 26.

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 571 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 1.1" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 4.3" 2.1" 2.2" 🚿 Regular watering
Jun 4.3" 1.2" 3.1" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.2" 3.1" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Sheridan 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 ~347 GDD — county provides 1,147 GDD Excellent fit

Mizuna Planting Timeline — Sheridan County, MT

Mizuna Planting Calendar

Activity When Date Range
Start Indoors April 5 Apr 5 – Apr 19
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 10 May 10 – May 31
Harvest June 21 Jun 21 – Jul 19
Fall Sowing June 26 Jun 26 – Jul 10

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 Fall Sowing 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 · 1-2 times/week

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: acceptable

🗺️ USDA Zone

Zone 3b

📆 Growing Season

124 days in Sheridan County

Growing Tips for Mizuna in Sheridan County

Direct sow Mizuna outdoors after May 17 in Sheridan County when soil has warmed and frost danger has passed.

Your generous 124.0-day season in Sheridan 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.

Sheridan County receives only 17" 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 Sheridan County, MT?

Sheridan County is in Zone 3b with an average last frost of May 17. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Sheridan County, MT?

Sheridan County, Montana is in USDA Hardiness Zone 3b. The average last spring frost is May 17 and first fall frost is September 18.

🌱

Your Sheridan County Garden Planner — Free

A 24-page printable planner built for Sheridan County (Zone 3b). 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 Sheridan 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.