Top 7 Tall Flowering Plants for Back of Borders

Home gardeners can mimic the success of professional landscapers by using plants of varying heights. These tall-growing plants do well for behind shorter flowers.

Flower lovers can try these tall growing plants in the back of the border, or center of an island planter, to create visual interest and draw the eye in. Remember, though, that not all cultivars of these flowering plants will provide the height you may be looking for so check individual labels to see which will grow tall enough to create interest in your garden.


Canna Lily

Canna lilies are known for their bold foliage and brightly colored flowers. While some dwarf cultivars are available as short as 1-2 feet, most cannas grow easily between 5-8 feet.

Mid-summer blooms top the plants in plumes of bold color, often in bright yellow, red or orange. Cannas are tender perennials only hardy to zone 7.



Also known as spider flower, the strong stems lift the unusually shaped flowers 3-6 feet tall. The rose, pink, white or purple colored flowers are spidery in appearance, giving the perennials their common name.

Weeks of blooms begin in early summer and continue through the first frost, but unless gardeners want volunteer seedlings they will want to deadhead the spent blooms.


Delphinium suave

A great vertical plant for cold climates, delphinium is hardy in zones 3-7 and prefers cooler summers that are not overly humid. The showy purple blooms attract butterflies and gardeners alike during the early summer blooming season each year. The larger cultivars of delphinium grow 4-6 feet tall.



An attractive, upright-growing plant that reaches between 2-5 feet tall, the foxglove is a biennial that will naturalize in favorable conditions.

The unique blooms grow well in full sun through part shade and foxgloves prefer evenly moist soil. Gardeners will want to take care not to let the soil dry out completely and to prevent the plants from getting too waterlogged.



Long a favorite for cutting gardens, hardy gladioulus plants can survive winters through zone 7 and grow up to 6 feet tall. Almost every color flower is available, and many bi-colors as well, giving an endless palette for the gardener to choose from. Blooms are fragrant and showy, creating a visual accent from late summer through early fall.



Another biennial, hollyhock is a tall, stately plant with large, saucer-shaped flowers. Another plant that, like delphinium, tolerates cold climates well, the hollyhock is hardy in zones 2-10.

Hollyhocks grow 5-8 feet tall but can be spaced more closely together than many other plants because the stalks are so tall and narrow. They look great planted against a fence, wall or other tall structure and are reminiscent of an old-fashioned cottage garden.



Both N. alata and N. sylvestris grow 3-5 feet tall and have a spread of about 2 feet. The fragrant blooms last from early summer through frost and provide an abundance of color in the garden. Flowering tobacco is a tender perennial and often treated as an annual.

Tolerant of part shade, ornamental tobacco is a favorite for night or moon gardens because certain cultivars bloom only in the moonlight while others are highly fragrant.