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When to Plant Mizuna in Oswego County, NY

Oswego County, New York Zone 5b May

May to-do list for Oswego County, New York

A quick May briefing for Oswego County, New York gardeners — what's urgent, what's next, and what can wait.

Avg. last frost May 7
Avg. first frost October 11
Soil temp (4") 60°F
Watering Low
Pest pressure Low
Daylight 14.5 hrs
  1. Time to transplant mizuna

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

A few tasks this May that'll pay off in June
  • 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.

Oswego County, New York is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is October 11, giving you a growing season of approximately 157 days.

At an elevation of 109 feet, Oswego County receives approximately 38.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Mizuna during the growing season.

Oswego County, NY (Zone 5b) Moderate season
157 days
Last Spring Frost May 7
157 growing days
First Fall Frost October 11
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Oswego County Soil Profile

Soil Type

Silt Loam

Soil pH

5.1-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (95 days to spare)
Start indoors: Mar 25 Transplant: Apr 29 🍅 Harvest: Jun 3 – Jul 1
Recommended (50%) ✓ Fits season (94 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jun 11 – Jul 9
Safe Start (90%) ✓ Fits season (100 days to spare)
Start indoors: Apr 13 Transplant: May 18 🍅 Harvest: Jun 22 – Jul 20

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 Oswego County

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

Soil pH

Your soil pH (5.1–6.2) is more acidic than Mizuna prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.1%). Annual compost additions will help Mizuna.

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

6
successive plantings in your 157-day season

Sow every 3.4 weeks. Last sowing by Aug 27 to harvest before frost.

For a dedicated fall crop, sow by Aug 02.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 2.8" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3" 0" ❄️ Dormant
Apr 3.1" 0" ❄️ Dormant
May 4.3" 3.9" 0.4" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 4" 0.3" 💧 Light watering
Aug 4.3" 3.2" 1.1" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 3" 1.3" 💧 Light watering
Nov 3.1" 0" ❄️ Dormant
Dec 2.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Oswego 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 ~572 GDD — county provides 2,394 GDD Excellent fit

Mizuna Planting Timeline — Oswego County, NY

Mizuna Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 23 Apr 23 – May 14
Harvest June 11 Jun 11 – Jul 9
Fall Sowing August 2 Aug 2 – Aug 16

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

Month-by-Month Timeline

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

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Natural rainfall sufficient

📅 Days to Maturity

30–45 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

157 days in Oswego County

Growing Tips for Mizuna in Oswego County

Direct sow Mizuna outdoors after May 07 in Oswego County when soil has warmed and frost danger has passed.

Your generous 157.0-day season in Oswego 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 Oswego County, NY?

Oswego County is in Zone 5b with an average last frost of May 7. Plan your Mizuna planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oswego County, NY?

Oswego County, New York is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is October 11.

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Your Oswego County Garden Planner — Free

A 24-page printable planner built for Oswego County (Zone 5b). 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 Oswego County, NY. 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.