Several months back I started narrowleaf milkweed plants (seeds from livemonarch.com). About a week ago I noticed the first caterpillar, and the next day the second. Today the one at the top of the photo left the plant and started looking for a spot to pupate. Also today, found 4 (!!) more caterpillars amongst the plants. I am beyond thrilled, I never expected to get monarchs actually laying eggs on these plants so soon.
Beautiful milkweeds also keep iguanas away, fyi for those in Florida