Vieja,

Adult Monarch Butterflies are able to nectar (feed) off all sorts of plant blossoms, similar to bumble bees. It's the larval caterpillar stage that can only feed off some variety of milkweed. But, there are tons of different species of milkweed (Asclepias), and your Asclepias tuberosa is just one of those. If you want to attract adult butterflies to your garden, I would encourage you to plant a variety of nectar-producing plants. Try visiting the Xerces Society. They have suggestions for pollinator attracting plants for different regions. Good luck.

Martha

Thank you Martha! Wonder if I'd recognize the Monarch caterpillar ..? I have loads of flowers that meander all over my big flower garden that seed & grow at random now ... annuals & perennials. I notice the black bumble bees esp. like the Asclepsias ...until now when the flowers became the fluffy seed pods that scatter all over just now!