You can grow asters of varying sizes; choose what you want. You could plant it in a pot and put the pot into the soil to control it. If the plant is cramped in the pot, it may become cramped (leggy or some other manifestation of stunted growth) but you should go to or contact a plant vendor and talk to them with the goal of purchasing a plant that will perform in the way you want it to.
You can grow asters of varying sizes; choose what you want. You could plant it in a pot and put the pot into the soil to control it. If the plant is cramped in the pot, it may become cramped (leggy or some other manifestation of stunted growth) but you should go to or contact a plant vendor and talk to them with the goal of purchasing a plant that will perform in the way you want it to.