I want to plant a Callistemon variety with yellow flowers in my garden, but will it still be attractive to hummingbirds? I know they like the red-flowered ones.
I can’t say with complete certainty, and it may take a little while for hummingbirds to discover this new addition to your garden, but according to the book Hummingbird Gardens by Nancy Newfield and Barbara Nielsen (Chapters, 1996), the genus Callistemon in general is attractive to hummingbirds. The authors quote a California gardener named Charlene Butler, who grows red, pink, and white-flowered varieties which “have flushes of bloom, and when they’re in bloom the hummingbirds go nuts.”
Just as insurance, you could plant perennials (such as Crocosmia ‘Lucifer,’ Salvia, Penstemon) which are known attractants near the Callistemon.