Thanks for your question Paul. Before I answer your question could you tell more about the planter. Is it free standing with a bottom (like a windowbox or pot) or more like a small retaining wall where there is no bottom and the plant can grow into the soil below? PeterB Peter, It is a small retaining wall planter without a bottom and ties back into the house. This planter is not in full sun but goes get quite a bit ob sun. It also runs between my house and the driveway. Thanks for clarifying Paul, Hardy perennials, shrubs and evergreens can be difficult to maintain in raised planters. This is because the planter will thaw and freeze repeatedly during late winter and early spring. Plants in the ground will stay frozen and dormant until the ground thaws in spring. Since a planter is raised up from the soil it will often thaw out during early warm spells in February or March. When this happens, it can lure the plants in the planter out of dormancy too early. The plants will start to grow roots and buds swell up with the first flush of growth. Of course normal, sub freezing weather returns and refreezes the planter. When this happens the new growth is killed and the shock of all this can kill the entire plant. It is for this reason you don’t often see hardy perennials or shrubs in raised planter…they have a hard time surviving. Having said that, I HAVE seen hardy plants in planter surviving and thriving. Those planters are usually in a location where there isn’t a lot of afternoon sun so the planter manages not to warm up enough during “false spring” weather and so the plants remain dormant. Perhaps your planter is in such a location and has enough mass to stay frozen in late winter. My suggestion for you would be to give Dwarf Alberta Spruce a try. They are slow growing and very hardy. If it is protected from the west and north wind, you could also try smaller rhododendron, azaleas and holly. Let me know how you make out. Peter B