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When to Plant Microgreens in USDA Zone 1a

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 1a, the average last spring frost is around June 15 and the first fall frost is around August 15, giving you a growing season of approximately 61 days.

Zone 1a Very short season
61 days
Last Spring Frost June 15
61 growing days
First Fall Frost August 15

Microgreens Planting Timeline — Zone 1a

Where Is USDA Zone 1a?

The map below highlights the states that contain Zone 1a. 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 1a

Activity When Date Range
Start Indoors May 4 May 4 – May 18
Transplant Outdoors June 15 Jun 15 – Jun 29
Direct Sow June 8 Jun 8 – Jun 29
Harvest June 22 Jun 22 – Jul 20
Fall Sowing May 23 May 23 – Jun 6

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

Month-by-Month Timeline

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

Free Zone 1a Planting Calendar PDF

Know exactly when to plant every crop in your zone. Get a printable month-by-month calendar customized for Zone 1a with start dates, transplant windows, and harvest times.

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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

-60°F to -55°F average annual minimum

Growing Season

61 days (Zone 1a average)

Planting Specifications

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

Succession Planting Microgreens in Zone 1a

11
successive plantings in Zone 1a's ~61-day season

Sow every 0.7 weeks for continuous harvest throughout the season.

Growing Tips for Microgreens in Zone 1a

Zone 1a has a short growing season (~61 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

💡
LED Grow Lights $25-60

Full-spectrum LED lights for starting seeds indoors when daylight is limited.

🔥
Seedling Heat Mat $15-35

Warm soil for faster germination of heat-loving crops like tomatoes and peppers.

🪡
Floating Row Covers $12-30

Protect plants from frost, wind, and pests while letting light and water through.

Frequently Asked Questions

When should I plant Microgreens in Zone 1a?

In Zone 1a, plan your Microgreens planting around the average last frost date of June 15. Start seeds indoors around May 4. Direct sow outdoors around June 8. Transplant seedlings around June 15.

Can Microgreens grow in Zone 1a?

Yes, Microgreens can grow well in Zone 1a, hardy in USDA zones 1a through 13b. Zone 1a has a growing season of approximately 61 days, which is sufficient for Microgreens (7-21 days to maturity).

When can I harvest Microgreens in Zone 1a?

In Zone 1a, expect to harvest Microgreens from June 22 – July 20. Microgreens takes 7-21 days from planting to harvest.

What is the last frost date for Zone 1a?

The average last spring frost in Zone 1a is around June 15, and the first fall frost is around August 15. This gives a growing season of approximately 61 days. These are 50% probability dates — actual frost dates vary year to year.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner — organize your planting dates for Zone 1a, track your crops, and plan your garden season from seed to harvest.

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Free download. Plan your entire garden season in minutes.

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: April 2026.