Usda Plant Hardiness Zone Map 2025 Pdf. Changes to the ohio map. For example, seattle, washington, and the city of austin, texas, are both in the usda hardiness zone 9a because the map is a measure of the coldest temperature a plant can.

And those changes could impact what thrives in your garden. For example, seattle, washington, and the city of austin, texas, are both in the usda hardiness zone 9a because the map is a measure of the coldest temperature a plant can.