I'm going to put out a hummingbird and an orial feeder this spring to see if I can get any to show up, but I'm not sure when the best time to put out the feeders is. One of my books says that orials are one of the last birds to arive in the spring and may not show up till late May. I'm not sure about the hummers tho. I did find a migration map online that showed the hummers starting to work their way up from the gulf coast area.
Going by this info I would guess that I still have quite a bit of time before I need to put out the feeders, but thought I would get some other opinions.