Not all plants with the ability to be perennial are hardy in all areas. This is why planting zones are so important. Knowing what zone you garden in will allow you to determine what plants will survive in your area.
The term perennial is generally reserved for plants with showy flowers, excluding ornamental grasses and other plants mainly grown for their foliage. The term herbaceous perennial further narrows the group to plants with soft, green stems that die back to the ground in colder climates. Trees, shrubs and other woody stemmed plants are excluded.