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Connecticut Planting Guide & Growing Season

Connecticut is in USDA hardiness zone with a growing season of 170 days. The average last spring frost is Apr 15 - May 15 and the average first fall frost is Sep 30 - Oct 31. Climate data based on Hartford.

USDA Zone Hardiness zone
Last Frost Apr 15 - May 15 Average spring
First Frost Sep 30 - Oct 31 Average fall
Growing Season 170 days Moderate season

Growing Conditions in Connecticut

USDA Hardiness Zone
Average Last FrostApr 15 - May 15
Average First FrostSep 30 - Oct 31
Growing Season Length170 days
Climate StationHartford
NOAA GridBOX

How Connecticut Compares

Compare Connecticut's growing conditions with states that have similar climates.

StateUSDA ZoneLast FrostFirst FrostSeason (days)
Connecticut (CT) Apr 15 - May 15Sep 30 - Oct 31170
Alabama (AL) Mar 1 - Apr 1Oct 25 - Nov 15220
Alaska (AK) May 15 - Jun 15Aug 15 - Sep 15105
Arizona (AZ) Feb 1 - Apr 15Oct 15 - Dec 15270
Arkansas (AR) Mar 15 - Apr 15Oct 15 - Nov 1210
California (CA) Jan 15 - Apr 15Oct 15 - Dec 31290

Frequently Asked Questions About Gardening in Connecticut

When should I start seeds indoors in Connecticut?

In Connecticut, the average last frost date is Apr 15 - May 15. Start most seeds indoors 6-8 weeks before this date. The USDA hardiness zone for Connecticut is undefined, with a growing season of approximately 170 days.

What USDA hardiness zone is Connecticut?

Connecticut falls in USDA hardiness zones undefined. This affects which perennial plants will survive winter and influences optimal planting times.

When is the first frost in Connecticut?

The average first frost date in Connecticut is Sep 30 - Oct 31. Plan to harvest cold-sensitive crops before this date or protect them with row covers.

How long is the growing season in Connecticut?

Connecticut has an average growing season of 170 days, from the last frost (Apr 15 - May 15) to first frost (Sep 30 - Oct 31). This moderate season works well for most common vegetables.

Plan Your Garden

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