Blog

When to Plant Microgreens in USDA Zone 3b

Zone 3b Zone 3b May

May to-do list for Zone 3b

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Zone 3b.

Avg. last frost May 16
Avg. first frost September 22
  1. Transplant microgreens outside

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

  2. Scatter microgreens into prepared beds

    Succession planting is the secret here. Put in a row now, another in 2 weeks, a third in 4.

  3. Bring in the microgreens

    Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.

To set up a strong June, finish these tasks
  • Starting indoors: microgreens
  • First harvests: microgreens
  • Fall sowing: microgreens
Send me my free Zone 3b Planting Guide →

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.

In Zone 3b, the average last spring frost is around May 10 and the first fall frost is around September 22, giving you a growing season of approximately 135 days.

Share this guide:
Zone 3b Short season
135 days
Last Spring Frost May 10
135 growing days
First Fall Frost September 22

Microgreens Planting Timeline — Zone 3b

Where Is USDA Zone 3b?

The map below highlights the states that contain Zone 3b. Click any state to see the Microgreens planting schedule for that location.

Prints a clean, ink-friendly version without maps or navigation.

Microgreens Planting Calendar — Zone 3b

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors May 10 May 10 – May 24
Direct Sow May 3 May 3 – May 24
Harvest May 17 May 17 – Jun 14
Fall Sowing June 30 Jun 30 – Jul 14

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

Month-by-Month Timeline

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

Free Zone 3b Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 3b with start dates, transplant windows, and harvest times.

Instant PDF download. No spam, unsubscribe any time.

Share this guide:

Growing Conditions

Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

Days to Maturity

7–21 days

Soil pH

6 – 7

Zone Temperature Range

°F to °F average annual minimum

Growing Season

135 days (Zone average)

Planting Specifications

Planting Depth0.5 inches
Plant Spacing2 inches apart
Row Spacing6 inches between rows

Succession Planting Microgreens in Zone

26
successive plantings in Zone 's ~135-day season

Sow every 0.7 weeks for continuous harvest throughout the season.

Growing Tips for Microgreens in Zone

Zone has a short growing season (~135 days). Start Microgreens indoors early and use season-extension techniques like row covers and cold frames.

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.

Saving Microgreens Seeds

Recommended for Your Garden

🌱
Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️
Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Frequently Asked Questions

When should I plant Microgreens in Zone 3b?

In Zone 3b, plan your Microgreens planting around the average last frost date of May 10. Start seeds indoors around March 29. Direct sow outdoors around May 3. Transplant seedlings around May 10.

Can Microgreens grow in Zone 3b?

Yes, Microgreens can grow well in Zone 3b, hardy in USDA zones 1a through 13b. Zone 3b has a growing season of approximately 135 days, which is sufficient for Microgreens (7-21 days to maturity).

When can I harvest Microgreens in Zone 3b?

In Zone 3b, expect to harvest Microgreens from May 17 – June 14. Microgreens takes 7-21 days from planting to harvest.

What is the last frost date for Zone 3b?

The average last spring frost in Zone 3b is around May 10, and the first fall frost is around September 22. This gives a growing season of approximately 135 days. These are 50% probability dates — actual frost dates vary year to year.

🌱

Your Free Printable Garden Planner

A 24-page printable planner tailored to your zone. Planting dates, monthly task lists, harvest log, seed inventory, and succession charts — everything you need to plan a full season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Planting dates are estimates based on average frost dates — 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.