Does camellia grow in Illinois

Do you mean naturally? I have no idea. But so far as gardens go: in what part of Illinois are you talking? I live in Springfield, which is on the border of the USDA's zones 5a and 5b, and I've had marginal success. I think it's recommended that you live at least in Zone 6a (southern Illinois) to safely grow camellia. If you create a "microclimate" by shielding them, or perhaps cover them in the winter as one would with roses, then you could probably grow them further north. Maybe you could see http://www.camforest.com for more info?