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When to Plant Microgreens in Hennepin County, MN

Hennepin County, Minnesota Zone 5a May

What to do in May

May is a pivotal month for Hennepin County, Minnesota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 23
Avg. first frost October 9
Soil temp (4") 55°F
Watering Low
Pest pressure Low
Daylight 14.7 hrs
  1. Fire up the seed-starting tray: microgreens

    Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.

  2. It's harvest week for microgreens

    If you can't use it all right away, check the food-preservation section of your planner.

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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.

Hennepin County, Minnesota is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 9, giving you a growing season of approximately 169 days.

At an elevation of 694 feet, Hennepin County receives approximately 36.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Microgreens to ensure they mature before fall.

Hennepin County, MN (Zone 5a) Moderate season
169 days
Last Spring Frost April 23
169 growing days
First Fall Frost October 9

Hennepin County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (135 days to spare)
Start indoors: Mar 13 Transplant: Apr 17 🍅 Harvest: Apr 24 – May 22
Recommended (50%) ✓ Fits season (134 days to spare)
Start indoors: Mar 19 Transplant: Apr 23 🍅 Harvest: Apr 30 – May 28
Safe Start (90%) ✓ Fits season (131 days to spare)
Start indoors: Apr 8 Transplant: May 13 🍅 Harvest: May 20 – Jun 17

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 Hennepin County

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

Soil pH

Your soil pH (6.1–7.2) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Microgreens.

Organic Matter

Organic matter is excellent (4.1%) — Microgreens will thrive.

How to Plant Microgreens

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Microgreens

33
successive plantings in your 169-day season

Sow every 0.7 weeks. Last sowing by Sep 18 to harvest before frost.

For a dedicated fall crop, sow by Jul 31.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 580 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 1.6" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.1" 0.2" 💧 Light watering
Aug 4.3" 3.7" 0.6" 💧 Light watering
Sep 4.3" 3.4" 0.9" 💧 Light watering
Oct 4.3" 3.2" 1.1" 💧 Light watering
Nov 2.3" 0" ❄️ Dormant
Dec 2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Hennepin 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 ~161 GDD — county provides 1,943 GDD Excellent fit

Microgreens Planting Timeline — Hennepin County, MN

Microgreens Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 – Apr 2
Transplant Outdoors April 23 Apr 23 – May 7
Direct Sow April 9 Apr 9 – Apr 30
Harvest April 30 Apr 30 – May 28
Fall Sowing July 31 Jul 31 – Aug 14

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 Harvest
May Transplant Outdoors Harvest
June
July Fall Sowing
August Fall Sowing
September
October
November
December

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

7–21 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

169 days in Hennepin County

Growing Tips for Microgreens in Hennepin County

Direct sow Microgreens outdoors after April 23 in Hennepin County when soil has warmed and frost danger has passed.

Your generous 169.0-day season in Hennepin 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 Hennepin County, MN?

Hennepin County is in Zone 5a with an average last frost of April 23. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hennepin County, MN?

Hennepin County, Minnesota is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 9.

🌱

Your Hennepin County Garden Planner — Free

A 24-page printable planner built for Hennepin County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Hennepin 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.