Verbena bonariensis
Verbena bonariensis is a very tall flowering herbaceous perennial with mostly basal leaves and branches of purple topped flowers that appear from mid to late summer through to the first frosts. This is a great plant for naturalistic or prairie gardens or at the back of a herbaceous border. I love it planted in amongst Stipa gigantea or Perovskia. It will self seed in your garden which I think is a great attribute in a plant and it will be swarmed by butterflies on hot sunny afternoons.
Common Name
purple top vervian, argentinian vervian
Height and Spread
1.5m x .45m
Cultivation
It prefers full sun and moist but well drained fertile soil. Possibly protect with a dry mulch in very cold winters. We leave the flower stalks on the plant to bring interest to the garden in winter - they are key plants in many frosty morning photos. Cut back in spring when you can see the new growth appearing.
Additional information
It is a great flower for wildlife - bees and butterflies are drawn to the purple flowers and the seeds are good for some birds. It can be used in informal, naturalistic flower arrangements, and it drops a lovely purple confetti.