Inconsistent Garlic size

[SueCT]

I grew Garlic for the first time this year, using the largest heads that were available in Agway for Music, Chesnok and German Red varieties. I planted all cloves from each head. I just finished harvesting and most bulbs were small, but overall were just very inconsistent. I got maybe 7 good sized large heads 2-2 1/2", more medium sized heads in the 1 1/2-2" range and quite a few small heads in the 1/-1 1/2" range. I am going to try again this fall, but I am not sure why I didn't get more consistent results and larger bulbs. Is it the size of the bulb it was taken from or the size of the clove you plant that matters? Did our odd weather cause this with the warm winter and late freezes after the bulbs had started to grow again? I have very high organic matter in my soil from all the compost and I mulched with straw heavily, but have not watered much, only a couple of times. Maybe not enough water? Any help will be appreciated, since i probably won't bother to keep growing it if I can't get a better, more consistent harvest of good size bulbs. To me, a "normal" size garlic bulb for cooking is at least 2-2 1/2" in size, at least that is what I usually buy.