Flower bulbs that bloom all summer include dahlias, cannas, gladiolus and lilies. A wide variety of dahlias are available that produce distinct and colorful blooms that may even bloom into the fall. Dahlias can grow in the spring when all danger of frost has passed.
Gardeners can use some varieties of dahlias as low border plants and others as part of tall background plantings. Dahlias grow from tuberous roots that require a sunny spot in a landscape. Dahlias are heavy feeders. Dahlias should grow in soil previously enriched with rotted manure, compost or bone meal. Larger varieties can be heavy and require stakes for support when growing.
Cannas bloom from early summer until the first frost. They are available in an array of colors that include red, yellow, cream and orange. Some cannas are dwarf varieties that only grow to 2 feet, while others may reach 5 feet or more.The canna rhizomes send out underground shoots and roots, so the planting soil should be fairly loose to a depth of 1 foot. Gardeners should cover the rhizome with 2 to 4 inches of soil and keep it moist. Stakes can keep the plants upright.
Gladiolus produce long-lasting blooms throughout the summer that are beautiful when added to bouquets or floral arrangements. They grow best in soil that is well-drained and in partial shade or sun. Adding composted manure as fall approaches can provide nutrients and prolong the bloom period.
Lilies grow from bulbs that are fleshy and produce big, colorful flowers. Many varieties bloom throughout the summer. They require well-drained soil and sun for at least half the day. Gardeners should plant bulbs deep enough so that they remain cool in high temperatures or full sun.