Jeanne, I have never started garlic inside, even in my greenhouses. Mine are all planted in mid-October to early-November in my raised garden or in large pots. I assume you divided the garlic into cloves and the cloves are what you planted, rather than the bulb. Right?
Garlic is like the vast majority of vegetables and needs direct sunlight to grow properly. You want those planted cloves to grow into bulbs and this growth is stimulated by the length of sunlight. I think by you growing it inside, or even if you planted it outside now, those cloves might grow larger, but I doubt you will get any bulb formation.
Keep in mind that the top growth is feeding the clove and without the top, green growth, the clove won't have the photosynthesized "food" to grow. So by cutting off the green stem/leaves, the cloves won't do anything. Being in moist soil, they would probably just rot.
If you want to (seriously) grow garlic there in Iowa, I would guess that you should plant your cloves outside in mid-September. I am guessing on that date. I want to plant mine approximately two months before we get into heavy winter weather.
