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Iowa Planting Guide & Growing Season

Iowa is in USDA hardiness zone with a growing season of 160 days. The average last spring frost is Apr 15 - May 1 and the average first fall frost is Oct 1 - Oct 15.

USDA Zone Hardiness zone
Last Frost Apr 15 - May 1 Average spring
First Frost Oct 1 - Oct 15 Average fall
Growing Season 160 days Moderate season

Growing Conditions in Iowa

USDA Hardiness Zone
Average Last FrostApr 15 - May 1
Average First FrostOct 1 - Oct 15
Growing Season Length160 days

How Iowa Compares

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

StateUSDA ZoneLast FrostFirst FrostSeason (days)
Iowa (IA) Apr 15 - May 1Oct 1 - Oct 15160
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 Iowa

When should I start seeds indoors in Iowa?

In Iowa, the average last frost date is Apr 15 - May 1. Start most seeds indoors 6-8 weeks before this date. The USDA hardiness zone for Iowa is undefined, with a growing season of approximately 160 days.

What USDA hardiness zone is Iowa?

Iowa 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 Iowa?

The average first frost date in Iowa is Oct 1 - Oct 15. Plan to harvest cold-sensitive crops before this date or protect them with row covers.

How long is the growing season in Iowa?

Iowa has an average growing season of 160 days, from the last frost (Apr 15 - May 1) to first frost (Oct 1 - Oct 15). This moderate season works well for most common vegetables.

Plan Your Garden

Use our seed starting calculator to get personalized planting dates, or browse all states.

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