Yes u can if u have the width which u do. U can make a square frame with wood around containers. With nails/screws half down going around square frame. Then use plant ties and gently pull branches down and away from center. Start with the tallest branch and get even with lower main branch. The wood is just an anchor u can probably just use the side of your container. Not only are u lsting to get height under control but u are also spreading the plants energy even to each branch when the tops are even. Lsting will not slow your plant down because you have a healthy plant. Beautiful plant keep up the good work