Iowa's USDA Plant Hardiness Growing Zones as of the 2023 update are primarily Zone 5, with the northern half of the state classified as Zone 5a and the southern half as Zone 5b. Small areas in northeast Iowa fall into Zone 4b, while small areas in southeast and southwest Iowa are classified as Zone 6a

. In summary:

• Northern Iowa: Zone 5a
• Southern Iowa: Zone 5b
• Small areas in northeast Iowa: Zone 4b
• Small areas in southeast and southwest Iowa: Zone 6a

These zones reflect average annual minimum temperatures and help gardeners select plants suited to Iowa's climate