If you are looking to make a tower that is a bit more complex, try the crooked version of this terra cotta tower. Their fashion begun a few years ago, but not too many people have heard of them before.
terra cotta pots in the following sizes: 14”, 12” 10”, 8”, and 6”
one 36” half inch dowel rod or 36” rebar rod
Place the pot in the place where you want your flowers to be. Put the soil into the pots (beware, when done, that your tower will be heavy) and add the soil moist. Place the rod in the center and just add another pot on top. Repeat this until you have your tower. All you have to do now is too add the flowers.