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When to Plant Microgreens in Ontario

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.

Ontario spans USDA hardiness zones 4a, 4b, 5b, 6a, 6b, 7a, 7b, 8a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Microgreens planting dates based on your local frost dates.

Microgreens Planting Calendar for Ontario

Zone 4a ~145 day growing season · Full guide →

Last frost: May 6 · First frost: September 28 · 145 day season

Activity When Date Range
Start Indoors March 25 Mar 25 – Apr 8
Transplant Outdoors May 6 May 6 – May 20
Direct Sow April 29 Apr 29 – May 20
Fall Sowing July 6 Jul 6 – Jul 20
Harvest May 13 May 13 – Jun 10
Zone 4b ~155 day growing season · Full guide →

Last frost: May 1 · First frost: October 3 · 155 day season

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Fall Sowing July 11 Jul 11 – Jul 25
Harvest May 8 May 8 – Jun 5
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Fall Sowing August 4 Aug 4 – Aug 18
Harvest April 25 Apr 25 – May 23
Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Fall Sowing August 11 Aug 11 – Aug 25
Harvest April 17 Apr 17 – May 15
Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Fall Sowing August 16 Aug 16 – Aug 30
Harvest April 10 Apr 10 – May 8
Zone 7a ~221 day growing season · Full guide →

Last frost: March 25 · First frost: November 1 · 221 day season

Activity When Date Range
Start Indoors February 18 Feb 18 – Mar 4
Transplant Outdoors March 25 Mar 25 – Apr 8
Direct Sow March 11 Mar 11 – Apr 1
Fall Sowing August 23 Aug 23 – Sep 6
Harvest April 1 Apr 1 – Apr 29
Zone 7b ~235 day growing season · Full guide →

Last frost: March 18 · First frost: November 8 · 235 day season

Activity When Date Range
Start Indoors February 11 Feb 11 – Feb 25
Transplant Outdoors March 18 Mar 18 – Apr 1
Direct Sow March 4 Mar 4 – Mar 25
Fall Sowing August 30 Aug 30 – Sep 13
Harvest March 25 Mar 25 – Apr 22
Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors March 8 Mar 8 – Mar 22
Direct Sow February 22 Feb 22 – Mar 15
Fall Sowing September 9 Sep 9 – Sep 23
Harvest March 15 Mar 15 – Apr 12

Growing Tips for Ontario

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 Ontario?

Planting dates for Microgreens in Ontario depend on your USDA zone. Ontario spans zones 4a, 4b, 5b, 6a, 6b, 7a, 7b, 8a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Ontario for planting?

Ontario contains USDA hardiness zones 4a, 4b, 5b, 6a, 6b, 7a, 7b, 8a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.