Perennials live for at least three years, although some survive for much longer. Many perennial species die back to the ground in winter and regrow in the spring. To identify purple perennials, note their foliage, form and flower type. Purple perennials add deep to bright colour to the landscape, and some species attract pollinating wildlife, such as birds, butterflies or bees, with their nectar. Plant species that bloom at different times during the growing season for constant colour.
Early blooming perennials start producing flowers in spring, which lasts from March to May. Purple-flowering species include the bugle weed (Ajuga reptans), a 15 to 22.5 (6 to 9 inch) tall perennial that spreads as a ground cover. Bugle weed blooms with small, purple, blue and white flowers that stand on inflorescences. Flowers have a forked lower petal and attract bees. Turkish veronica (Veronica liwanensis) blooms in late spring with purple to blue flowers on tall racemes. The small blossoms grow from the bottom to the top. Turkish veronica grows to 60 cm (2 feet) tall and has lustrous, evergreen leaves. This perennial can be grown as a spreading ground cover.
The summer blooming season begins in June and lasts through August. The purple coneflower (Echinacea purpurea) produces purple, pink and white daisy-like blooms with dark gold centres in summer. The conflower's long-lasting blossoms grow from 6.3 to 12.5 cm (2 1/2 to 5 inches) in diameter and have 12 to 20 drooping petals. Purple coneflowers have rough leaves, hairy stems and grow from 30 to 90 cm (1 to 3 feet) tall. Lavender (Lavandula angustifolia ) blooms through the summer months with fragrant spikes of small, pale to deep purple blossoms. Lavender has aromatic, grey-green foliage and grows from 60 to 90 cm (2 to 3 feet) tall. It grows in upright clumps and has stippled leaves that turn silvery in winter.
Late summer to autumn bloomers
Late-blooming purple perennials produce flowers from August until September, though sometimes blossoms last until the first killing frost. Catmint (Nepeta spp.) blooms in late summer with tall spikes of violet to blue flowers. This relative of the catnip plant has fragrant flowers and foliage and grows from 30 to 90 cm (12 to 36 inches) tall. Russian sage (Perovskia atriplicifolia) flowers from July through October. This aromatic perennial produces tall spikes of purple-blue flowers and grows in an upright form. Russian sage grows from 90 cm to 1.5 m (36 to 60 inches) tall and has grey-green, fragrant foliage.
Some purple perennials bloom for much of the growing season. These include the creeping heliotrope (Heliotropium amplexicaule), which flowers from summer to autumn. This spreading plant produces clusters of tiny, tublular, blue to purple blossoms and grows from 15 to 30 cm (6 to 12 inches) tall. Bergamot (Monarda hybrids) bloom all summer long with purple, red or pink flowers. This perennial's flowers have spiky, thin petals and upright stamens. Bergamot grows from 60 cm to 1.2 m (2 to 4 feet) tall and attracts bees, hummingbirds and butterflies.