I can't find tomato cages in garden centers and bamboo is not handy in open ground I think.
Is it a good idea to make the diameter small so the plant will grow out the cage? Then the branches are supported close to the main stem.
YOU CAN ALSO MAKE THEM FROM HEAVIER GAUGE STUFF TOO LIKE
THE heavy gauge RENFORCING MESH FOR CONCREATE (not the fine stuff they sell in they sell inside) Home depot sells it
i think they call it remesh
they usually store it outside
cut it to desired size cut off one or two of the bottom horizontal supports and you have your ground stakes
its a litlle bit of work but works great there durable and will last a long time