Does anyone have any experience growing Purple Milkweed (Asclepias purpurascens), Showy Milkweed (Asclepias speciosa), Davis Showy Milkweed (Asclepias speciosa 'Davis'), Spider Milkweed (Asclepias viridis), or Poke Milkweed (Asclepias exaltata) in a garden?
I need to know if they clump or spread, how much shade (if any) they will tolerate, and how far apart to space the plants. I think the Showy milkweed may be too spreading for my smaller gardens, but I could not find any information on whether or not the Davis variety has a similar habit.
Any information on any of the above varieties would be greatly appreciated.
Western New York