Usda Plant Hardiness Zones 2024. The new hardiness zone map released this year has been created using gis (geographic information system) to examine hardiness zones at a much finer scale. In warmer climates (zones 8 and above), they can be left and pruned in early spring.' this perennial salvia x sylvestris from nature hills flowers with deep purple.
The usda hardiness zone map is a valuable tool for assessing plant hardiness based on average annual extreme minimum winter temperatures. Wherever you buy your seeds, or plant starts.