Italian chives will have pretty lavender flowers and garlic chives will have a white flower. All my chives bloomed in early spring. Onions do flower and often it will be the second year that they'll flower. As soon as I see my onions begin to form that flower stalk, I cut it off near the ground. I want the energy directed into the bulb rather than flower.
I have never grown Elephant garlic (which isn't even a garlic) but my guess would be that it flowers similar to the onion.