Summer bulbs are tender and need warm soil. Some popular bulbs for summer are alliums, tuberous begonias, cyclamens, dahlias, gladiolus, lilies, and ranunculus. Summer bulbs are planted in the early spring and are often staggered when planting several bulbs of the same species. I alternate my planting schedule for gladiolus for different blooming times. Spacing the planting for a week allows a longer blooming period for the flowers. Summer bulbs are often planted in raised garden beds or combined with summer-blooming annuals and perennials.
There are many ways you can plant bulbs. Bulbs are popular in rock gardens. Good choices for a rock garden are crocuses, bulbous irises, and tulips. You can also add a combination of grape hyacinths, scilla, and American Columbine. The columbine plantings will eventually self-sow. Water frequently for best results during the blooming season.
Cited work: Barbara Damrosch and Regina Ryan, The Garden Primer ( Workman Publishing, New York, 2008), 491.