How 'hardy' hardy verbena is may be up to some discussion. Arguably the hardiest is 'Homestead Purple', a naturally occurring hybrid discovered in an abandoned southern garden by perennial guru Alan Armitage and woody plant authority Michael Dirr. The botanical name is simply Verbena 'Homestead Purple'. There are other, so-called hardy verbenas but they tend not be as robust as Homestead Purple.

Although this plant is rated to at least zone 7, it can successfully overwinter in zone 6. But winter hardiness is tied into siting and soil conditions - it needs a very sunny location and very good drainage. Wet soils in winter will certainly affect how well it will survive. Here in my PNW zone 8 with typically wet winters, it is often hit pretty hard when temps drop much into the 20's.

It can get taller than 4" -- as much as 8-10" if happy. And it can spread rather vigorously as well, so doesn't always play well with other small perennials. But it does bloom very heavily off and on throughout summer.

Thanks, gardengal! The bank is very sunny (pretty much from sunrise to late afternoon). Whatever we plant on the bank will just be a groundcover so we're not worried about it crowding out other plants. I don't think it'd like the bitterly cold winters here in PA. The banks are right next to the road too, so maybe something a little tough that can stand up to the snows in the winter and recover in the spring. So many choices. I don't know how mom and dad feel about it but I think a honeysuckle (NOT the Japanese variety) or other flowering vine would look spectactular on the larger bank.

Brad AKA Moonwolf