I'm growing several summer bulbs this year. These include cannas, caladium, and elephant ears. Summer bulbs are summer-blooming plants that have some type of underground storage structure, but most of them don't look like bulbs.
The vast majority of summer bulbs are not cold hardy and will not survive our winters. They are often referred to as 'tender' bulbs. These plants need to be dug up at the end of the season, and the storage structure kept indoors until the following planting season--after the danger of frost has passed.
Tuberous begonias grow from a tuber. The plants range from 12 to 18 inches tall, and there are also trailing types. They come in a wide range of flower colors, from pastels to brights. Bloom time is from summer into autumn. Begonias do best in partial shade. Keep the soil evenly moist, but not wet.
Caladiums also grow from a tuber. These plants reach 1 to 2 feet in height and have colored foliage in a mix of red, pink, green, and white. These plants are grown for their beautiful foliage, not flowers. They do best in partial shade, although some newer varieties do tolerate sunnier locations. Keep soil evenly moist, but not wet.
Cannas grow from a rhizome. The plants range from 2 to 7 feet tall, depending on the variety grown. Cannas are grown for both flowers and foliage. They come in a wide variety of flower colors--red, orange, yellow, pink, and some bicolors. Some cultivars have colored foliage as well. Bloom time is summer into autumn. They prefer full sun, and the best growth occurs in a rich soil with a good supply of moisture.
Dahlias grow from tuberous roots. Plants range from 1 foot to 8 feet tall. There is also a wide variety of flower types, including anemone-flowered, ball, pompom, cactus, semi-cactus, and others. Dahlias also come in a wide range of flower sizes and colors. Bloom time is from summer into fall. Most dahlias will need staking.
Elephant ears grow from corms. There are three or more types of plants available under the common name of elephant ear. Most commonly found are the colocasia, alocasia, and xanthosoma.
You can also find information on these and other exotic plants on University of Illinois Extension's Tropical Punch website at http://extension.illinois.edu/tropicalpunch/.