I have large metal cages (for tomatoe plants originally) .
I place one in a large, 20 inch, container and plant the peas on the edge of the container.
Then I can grow --- a delphinium--- or sunflower----or ??? in the center.
Or do it the other way, and grow peas in center and petunias ( or other dwarf plants) on the edge.
Or scatter the peas seeds across the container, and scatter carrot seeds too.
