Donna, are you sure they're talking about ALL milkweed? There is a variety-- Tropical Milkweed, also known as Mexican Milkweed ( Asclepias Curassavica) --that is not native to the U.S. at all but has been introduced to the warmer areas. Here's a link to milkweed species by area --scroll down because CA is at the bottom of the page.
https: //monarchjointventure.org/images/uploads/documents/MilkweedFactSheetFINAL.pdf
Donna, are you sure they're talking about ALL milkweed? There is a variety-- Tropical Milkweed, also known as Mexican Milkweed ( Asclepias Curassavica) --that is not native to the U.S. at all but has been introduced to the warmer areas. Here's a link to milkweed species by area --scroll down because CA is at the bottom of the page.
https: //monarchjointventure.org/images/uploads/documents/MilkweedFactSheetFINAL.pdf