Plant flowers for a summer garden that will bloom continuously for a season or that will reappear every year. Annuals, such as petunias or begonias, are good choices for a summer container garden. Perennials, such as Stella Dora daylilies, peonies and roses will reappear annually, year after year.
Canna lilies, daylilies and Asiatic lilies are all flowers that may bloom in your garden during the summer. Stately cannas may reach heights of 8 feet, while Asiatic and other types of daylilies grow between 1 and 4 feet tall. Lilies grow from bulbs and reappear year after year for an average of six seasons. Plant lilies in well-drained soil in your garden where they will receive full sun to partial shade. Flower colors vary from bright yellow to deep red; Asiatic lilies are the most fragrant. Liles work well in cut flower arrangements; the blossoms can last several days if kept in fresh water. Depending on the cultivar, lilies are hardy from zones 8 through 12 and may bloom from May to October. If you live in cold climates, you may need to remove the rhizomes from the ground when the plants are dormant and store them during the winter.
Hardy in zones 7 to 11, dahlias bloom in the summer from tender tubers. In much of the United States, dahlias must be dug up in the winter for protection and then replanted in the spring. Plant heights range from 12 inches to 8 feet tall, depending on the cultivar. Flower sizes also have a wide range from 2 to 12 inches in diameter. Plant dahlias in the spring after all threat of frost has passed. Dahlias varieties are available in shades of pink, yellow, white, red, purple and orange.
Gladiolus, also known as the sword lily, has spikes of showy flower blossoms during the mid-summer months. Plant gladioli corms in the spring, after the last frost and when the soil is warm. Gladioli grown between 2 and 6 feet tall, prefer full sun and well-drained soil. Gladioli have a large color range, from apricot to purple to multi-colored varieties. Hardy in zones 6 through 10, plant gladioli bulbs in two week intervals for more continuous summer flowers. Remove and store gladioli bulbs over the winter if you live in a colder climate.
Hollyhocks may be annuals, biennials or perennials that can grow over 9 feet tall and bloom during the summer, from late June to August. Varieties may be hardy from zones 4 to 8, depending on the care management. The biennial varieties alternately produce leaves or flowers. Hollyhock flowers bloom along tall stems in a succession with colorful blossoms in shades of red, yellow, white and pink.