6. Josephine clematis
height: 2.5 m, width: 85 cm, Zone 4
Few double-flowered clematis rebloom in fall, but Josephine hardly rests at all between flowering cycles, producing 11-cm-wide lilac blooms over an unusually long period. A naturally occurring sport of unknown parentage, Josephine is also well-adapted to container growing. Discovered in the U.K. by amateur gardener Josephine Hill, it was introduced by clematis guru Raymond Evison (The Guernsey Clematis Nursery) in 1998, and to Canada in 2004.
7. Black lace european elder
(Sambucus nigra 'Eva')
height: 1.8 m, width: 2.2 m, Zone 4
Intense purple-black, deeply dissected foliage with pale pink flowers in summer followed by black berries. Often used as a substitute for purple-leaved Japanese maples in colder zones, where it behaves more like a herbaceous perennial. In early spring, trim branches to seven to 13 centimetres from the ground. Bred at East Malling Research Centre in Kent, England; introduced to Canada in 2004.
8. 'Pink double delight' purple coneflower
(Echinacea purpurea 'Pink Double Delight')
height: 55 cm, width: 35 cm, Zone 3
The cone portion of this coneflower has been transformed into pink petaloid structures that look like rosy pompoms perched atop tidy, compact plants. Purists may shudder, but this deer-resistant and butterfly-attracting flower produces non-stop blooms from mid summer right into fall, provided it is deadheaded regularly. Bred by expert Echinacea hybridizer Arie Blom for AB-Cultivars of Holland and introduced to Canada in 2008.
9. 'Stairway to heaven' Jacob's ladder
(Polemonium reptans 'Stairway to Heaven')
height: 35 cm, width: 40 cm, Zone 3
Variegated forms of Jacob's ladder have been around since Elizabethan times, but they were always short-lived sports of the species P. caeruleum (such as Brise d'Anjou). Enter Bill Cullina from the New England Wildflower Society, who discovered a naturally occurring variegated form of P. reptans in a Massachusetts nursery that's vigorous and reliably perennial. The pale blue flowers in early summer are a bonus; introduced in 2004.
10. Plum vein petunia
(Petunia x hybrida [Easy Wave Series] Plum Vein)
height: 25 cm, width: 95 cm, Annual, tolerates 5ºC for short periods
Petunia popularity was on the wane until breeders at Pan Am Seeds began back-crossing garden varieties with wild species in the 1980s. There are now five different Wave Series, and Plum Vein from the Easy Wave Series is one of my favourites. Other plant breeders have jumped on the bandwagon, so now gardeners have a variety of vigorous, weather-resistant, spreading petunias to choose from that flower non-stop and don't require deadheading.
Photo: Heuchera 'Key Lime Pie,' courtesy of Proven Winners