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When to Plant Microgreens in Winona County, MN

Winona County, Minnesota Zone 4b May

Winona County, Minnesota gardeners: here's your May plan

A quick May briefing for Winona County, Minnesota gardeners — what's urgent, what's next, and what can wait.

Avg. last frost April 30
Avg. first frost October 7
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Basket week: microgreens

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

A few tasks this May that'll pay off in June
  • Starting indoors: microgreens
  • First harvests: microgreens

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Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.

Winona County, Minnesota is in USDA Zone 4b. The average last spring frost is April 30 and the first fall frost is October 7, giving you a growing season of approximately 160 days.

At an elevation of 1,396 feet, Winona County receives approximately 37.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80°F, so choose short-season varieties of Microgreens to ensure they mature before fall.

Winona County, MN (Zone 4b) Moderate season
160 days
Last Spring Frost April 30
160 growing days
First Fall Frost October 7

Winona County Soil Profile

Soil Type

Silt Loam

Soil pH

6.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (124 days to spare)
Start indoors: Mar 14 Transplant: Apr 25 🍅 Harvest: May 2 – May 30
Recommended (50%) ✓ Fits season (125 days to spare)
Start indoors: Mar 19 Transplant: Apr 30 🍅 Harvest: May 7 – Jun 4
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Apr 3 Transplant: May 15 🍅 Harvest: May 22 – Jun 19

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 Winona County

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

Soil pH

Your soil pH (6.3–6.8) is within Microgreens's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (5.2%) — Microgreens will thrive.

How to Plant Microgreens

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

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

Succession Planting Microgreens

31
successive plantings in your 160-day season

Sow every 0.7 weeks. Last sowing by Sep 16 to harvest before frost.

For a dedicated fall crop, sow by Jul 15.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 37 gal / 100 sq ft

Monthly Watering Guide for Microgreens

Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Microgreens Needs Rainfall You Supplement Action
Jan 1.7" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.5" 0" ❄️ Dormant
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 4.2" 0.1" 💧 Light watering
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 4.1" 0.2" 💧 Light watering
Sep 4.3" 2.8" 1.5" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 1.9" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Winona County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Microgreens 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.

Microgreens needs ~140 GDD — county provides 1,600 GDD Excellent fit

Microgreens Planting Timeline — Winona County, MN

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 30 Apr 30 – May 14
Direct Sow April 23 Apr 23 – May 14
Harvest May 7 May 7 – Jun 4
Fall Sowing July 15 Jul 15 – Jul 29

Plant 0.5" deep · 2" apart · Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

160 days in Winona County

Growing Tips for Microgreens in Winona County

Direct sow Microgreens outdoors after April 30 in Winona County when soil has warmed and frost danger has passed.

Your generous 160.0-day season in Winona County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.

General growing tips

Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.

Frequently Asked Questions

When should I plant Microgreens in Winona County, MN?

Winona County is in Zone 4b with an average last frost of April 30. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Winona County, MN?

Winona County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is April 30 and first fall frost is October 7.

🌱

Your Winona County Garden Planner — Free

A 24-page printable planner built for Winona County (Zone 4b). 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 Winona County, MN. 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.