Tall perennial flowers make elegant backdrops for garden beds and borders. Their height allows these plants, and their flowers, to rise above other plants and shrubs and can give a professional, layered appearance to any garden or pack more colour into a small space. Also, the flowers themselves are often useful for bouquets and arrangements and can be dried and used for potpourri.
Agastache has the common name of anise hyssop due to the liquorice-like smell with hints of citrus that it releases when broken apart. The flowers are full of nectar and commonly attract bees, butterflies and hummingbirds. The plant grows to between 2 and 3 feet in height and has lavender shoots of flowers that bloom in late summer.
Baptisa can grow even higher than agastache reaching heights of up to 7 feet. Also known as wild indigo, the flowers that bloom in early spring or fall in vivid indigo blue with white or yellow spots or flecks. Baptisa is also very disease resistant. The flowers are often used in arrangements or dried for potpourri.
Delphinium Black Knight
The 'Black Knight' delphinium grows to between 5 and 6 feet and is named for its groupings of dark, dark leaves. The plants blooms in June and July, shooting spikes of blue flowers upwards towards the sky. Delphiniums prefer full sun and need to be fertilised every month. They can be cut back after the first bloom to promote further flowering. Also, as an important side note, most delphiniums are poisonous and so should not be planted in gardens frequented by pets or young children.
Hollyhock is another towering perennial that grows to up to 7 feet tall. In midsummer Hollyhock spews forth multicoloured flowers that are perfect for arrangements and serve to brighten any garden wall or fence. Hollyhocks are susceptible to hollyhock rust, a fungal disease that can kill most of the plant's leaves if not treated early with a fungicide.