Yep, shouldn't be a problem if you keep the soil fertility reasonably high and you're planting hardnecks. I normally grow most in the ground but due to work in another state I grew out a few cloves in 12" pots this year - 2 per pot of Killarney Red since they're compact to begin with - and ended up with 2" heads. You'll need to have full sun and keep them watered well especially during bulb formation but you can easily get both a section of garlic for heads and another, planted closely, for garlic scallions in a 1/2 whiskey barrel.