There are so many species and varieties they vary in which zones they grow in, but I'm 8a here and have quite a number of them successfully growing. I've seen them growing in gardens in Bhutan so they can get quite hardy. But there are some that aren't hardy to my area and I lost them. They are pretty drought tolerant too, and shouldn't need watering once established, but all the same they can cope with ocassional wet feet, and mine like being beside the dam.
Callistemons attract birds by the flowers due to the nectar, so mainly nectar feeding birds. I don't know what nectar feeding birds you have in your area, here we have Honeyeaters, Lorikeets, sunbirds. We don't have hummingbirds, but we have a honeyeater that acts and looks a little like one. The flowers can attract insects, which also can bring birds. They are also good bushy shelter for small birds, especially when planted by a pond or water feature. They don't have berries, they have dry seed capsules with tiny seeds inside. These are not hard to germinate, but they don't tend to seld seed for some reason.
They flower mostly over spring and summer, especially summer, but some go right through Autumn too, and while most are red or crimson, there are a range of colours from white through cream, yellow, bright green, soft to deep pink, mauve and purple.
