There are a number of ways to ensure that your garden has a succession of bloom through the season. One is to interplant bulbs and flowers that bloom at various times. For example daffodils will bloom early in spring then dieback. You can plant them in the same area as hostas or summer-blooming perennials, which will emerge later and cover up the dying bulb foliage.
You can also plant flowers in drifts of 3 to 5 plants, placing plants with different bloom times next to one another. For example, you could plant irises that bloom in late spring near purple coneflowers that will bloom in mid- to late summer and/or chrysanthemums and asters that will bloom late summer to fall.