Quite a lot of stonecrops are relatively hardy. Many types of sedum thrive in USDA hardiness zones 4-9, and a few are hardy as low as zone 3, such as sedum acre, for example. Broadleaf stonecrops and Hylotelephium sieboldii like October Daphne are amongst the hardiest stonecrops you can grow. Hylotelephium telephium such as 'Herbstfreude' (Autumn Joy) also has a good level of hardiness.