Larger plants should be placed behind smaller plants, and you'll need more than one group of each species to spread the color around. Try tulips, daffodils, crocus or hyacinth. Candytuft and creeping phlox are short in size, making them ideal for your garden's foreground. Peony and iris are popular choices for late spring color. Day lily provides early summer color, while daisy is best in mid-summer, and tall phlox blooms in late summer.
Chrysanthemums also provide late summer color, while aster blooms in early fall.