Any time once the soil had warmed up a bit.

Plant any of the above at any time mid autumn to early spring. Resist planting anything if you have hard frost on the ground to avoid digging in the frost/ice. Don't forget that plants still need water in cold weather, especially new plants and pots. Owdboggy is right to avoid any die back, though bare-rooted plants will be good. Transplant from pots on a frost free day to avoid air burn damage to any rootlets.