Square containers are fun to work with. It seems  to give a person more room to plant in. Or plants seem to fit in their corners better.  I also seem to favor designing squares on an angle.

Here I put a Coleus in the back corner and finished with a Lotus vine in the front corner. The Red Spike is in the center. Either side of the Red Spike is 4 other plants, back to front depending on their growth height.

“The Container Design Potting Bench” has the Plan-O-Grams and this sample ready to view.

From your container designer guru.