1. ‘Canon J. Went’ Toadflax

Name: Linaria purpurea ‘Canon J. Went’

USDA Hardiness Zones: 5 to 8

Size: 18 to 36 inches tall and 1 foot wide

Conditions: Full sun to partial shade; dry to average soil

The delicate, upright ‘Canon J. Went’ toadflax is not an in-your-face plant but a stalwart long bloomer that will make you wonder why you didn’t fall in love with it long ago. Its mild manner; drought tolerance; willingness to grow despite neglect; and continuous bloom of soft, pastel pink flowers atop ferny, gray-blue foliage will win you over. Butterflies and bees love this plant.

2. ‘Georgia Blue’ Speedwell

Name: Veronica peduncularis ‘Georgia Blue’

Zones: 6 to 8

Size: 6 to 8 inches tall and 2 feet wide

Conditions: Partial sun to light shade; moist, well-drained soil

‘Georgia Blue’ speedwell is a tough, mat-forming ground cover that grows thick enough to suppress weeds. It tolerates neglect and drought once established. In early spring, long-lasting, cobalt blue flowers cover the plant, making it ideal for massing or as foreground for a succession of later-flowering perennials. In winter, the foliage takes on bronze hues.

3. Fringe Cups

Name: Tellima grandiflora

Zones: 4 to 8

Size: 30 inches tall and 18 inches wide

Conditions: Partial to light shade; moist, rich, well-drained soil

Fringe cups, an exuberant Pacific Northwest native, happily fills in shady, moist banks, covering bare areas where needed without being invasive. It tolerates the dry spells of summer without supplemental irrigation, which makes it a perfect perennial to naturalize a road bank. The flower spikes, which start out a delicate yellow and then fade to pink, are a child’s delight when viewed up close, making them the perfect pick for a bouquet.

4. Red Valerian

Name: Centranthus ruber

Zones: 5 to 8

Size: 2 to 3 feet tall and wide

Conditions: Full sun to partial shade; well-drained soil

Butterflies have gathered around this cottage-garden staple for generations, attracted to the watermelon-colored spires, which bloom their hearts out all summer. Deadheading red valerian just a couple of times over summer will prolong the bloom, and the removal of any unwanted seedlings is easy. This tough, drought-tolerant perennial makes a great addition to a cottage-style roadside garden.

Photos: (1, 3 and 4), Jerry Pavia; (2), Bill Johnson