Iowa's planting zones according to the 2023 USDA Plant Hardiness Zone Map are primarily Zone 5. The northern half of Iowa is mostly in Zone 5a, while the southern half is in Zone 5b. There are small areas in northeast Iowa classified as Zone 4b, and small areas in southeast and southwest Iowa fall into Zone 6a

. In summary:

• Northern Iowa: Zone 5a (with some areas in 4b)
• Southern Iowa: Zone 5b (with some areas in 6a)
• Small pockets in northeast Iowa: Zone 4b
• Small pockets in southeast and southwest Iowa: Zone 6a

This zoning reflects the average annual minimum temperatures and helps gardeners select plants suited to Iowa's climate