I have not had any issues with gophers on three different Asclepias types including speciosa.

I use a lot of wire baskets too, though I am switching to wired beds (essentially giant baskets 2' x 4')

Chad, Thank you much. I'm out there right now digging out the area for the asclepias and I'd decided to just go with it and forget the baskets. I've been planting in wire for 30-some years and do them as I need them, but was really dreading doing 30 at once...slows you down, ya know?.......LOL...I've got the speciosas ready to plant and some purpureas and fascicularis coming along soon....