Verbena bonariensis produces lavender flower heads formed from tightly45clustered florets held stiffly upright on branching stems these long45lasting blooms are a magnet for bees and butterflies and this elegant perennial is at its most effective when planted in large swathes verbena bonariensis is enjoying a resurgence in popularity associating beautifully with grasses in a tranquil planting scheme or adding a touch of architectural style to the back of herbaceous borders height 2