Hummingbirds are most attracted to the colors red, pink, orange and violet, so planting flowers in those colors--especially tubular flowers--will ensure you are successful in luring the little birds to your garden. It is also important to remember that hummingbirds visit flowers to feed, not because they are attracted to the smell or beauty of particular flowers. Planting flowers that produce a lot of nectar is much more important than planting for fragrance or attractiveness.
Spring Flowering Bulbs
Irises top the list of spring flowering bulbs that hummingbirds love. The best thing about them is their diversity--Iris species number between 200 and 300 and cover nearly every color in the rainbow (hence the name, which is Greek for rainbow).
Tulips, (Tulipa species) which are also colorful and varied, are another hummingbird favorite; as are the daffodils and paperwhites (Narcissus species).
Alliums, (onions and garlic) are perhaps surprising additions to the flower garden, but they actually smell wonderful and will bloom in both spring and fall during the cooler seasons.
Summer Flowering Bulbs
Belamcanda (Iris domesticus, formerly Belamcanda chinensi) is a spectacular summer flowering bulb with interest that continues into the fall. When blooms are spent, the seed heads burst open to reveal a cluster of shiny black seeds resembling blackberries, giving rise to its other common name, blackberry lily.
Another lily-like species, the Tiger lily or Day lily (Hemerocallis spp.) is attractive for a long time, blooming constantly and providing hummingbird food all summer.
Liatris (all Liatris species) is a lovely native wildflower coming in a variety of sizes and upright shape, all violet-colored.
Gladiolus and Cannas are other excellent bulb choices for hummingbirds that, depending upon varieties chosen, will bloom from May through late fall. Tuberous begonias and Crocosmia are also good summer bloomers.
Fall Flowering Bulbs
Dahlias are an excellent choice for late summer and into the fall--with at least 36 species and thousands of hybridizations, there is one for every place in your garden. They will provide hummingbirds a source of nectar in the fall months when there are fewer other flowers available.
Cranesbill or garden geranium, (Geranium species) should not be confused with the "other geraniums," (the pelargoniums). There are over 400 species and with bloom times ranging from May through November, they are extremely important sources of late nectar for hummingbirds.