I’ll have to try the cinnamon next year. I ended up sprinkling diatomaceous earth around the bottom of it and that seemed to help. But I’m not sure how often a monarch caterpillar might move to another plant so I was worried the DE may harm them too.
Some of the plants do have aphids, but not all my plants with ants on them had aphids (at least that I could find). I know ants will sometimes carry aphids, so maybe they were scouting out new plants?
Mine are all in the ground