V. bonariensis is a tall perennial with erect, branching stems to 2m in height, bearing sparse, oblong leaves and numerous branched clusters of small, purple flowers from summer to autumn.
Verbena bonariensis has tall, narrow, sparsely-leafed stems on top of which flattened heads of bright lavender-purple flowers appear in late-summer. It’s perfect for bringing height to an ornamental border and also works well in prairie-style planting schemes with ornamental grasses. It’s a superb butterfly plant, rivalling even buddleja.
Grow Verbena bonariensis in moist but well-drained soil in full sun. Given the right conditions, plants will self-seed freely, but in colder regions they may need protection from frost. Leave dead stalks to provide winter interest and mulch annually with well-rotted manure or compost. The Royal Horticultural Society has given it its Award of Garden Merit (AGM).