First, select the tree. Then, find out the root ball's size and how big your tree will get. These attributes of the tree will then help determine what planter you will need.
Tree Size – Ideally, you'll want to have about 2 cubic feet of space in your planter for every square foot of canopy – the width of the tree's branches at maturity.
Planter Weight – Your tree planter must be heavy enough to act as a sturdy base for your tree. For a larger tree, you'll need a larger planter to ensure the tree remains grounded as it grows. Remember, larger trees will catch more wind, making them more prone to tipping if they're in a planter that's too small and light.
Maturity Level of Trees – If you're looking to purchase a tree planter that will act as the forever home for the tree you put in it, you may want to consider seeking trees that are near maturity. This is because, if you plant a tree into a pot that's significantly bigger than its current root system, the soil that doesn't come into contact with roots can go bad. This means that less mature trees may need to start in a smaller container and then be moved into a final pot. Trees that are closer to maturity will help cut the guesswork out of picking the right tree planter.
to learn more about selecting the best planter for a tree.