My callistemon have all kept their leaves this mild winter (so far). Would love to know how many years from seed to bloom. Also anyone know of any real 'hardy' species.
Hardier ones bloom small. Various high altitude wild origin introductions have been found to be hardiest, some of these have yellow or greenish flowers. These are described in manuals and on web sites. A reddish one that has been on the local market with a distinctive name is 'Woodlanders Hardy'.
I've had good success with C. siberei, and Ian in Oylmpia had seed from some (C. viridiflorus, a cultivar he called C. 'Soft White' and C. subulatus) he claimed where quite reliable. There where others but those are the species I picked up, and as seedlings, flew through this winter.
I can see what Ron means about hardier ones blooming small. I'm trying viminalis, viminalis 'Capt.Cooke' and another from England that I've long since lost the label for. Now if they would only bloom for me. They will be going into their 3rd year.