Karen says: The milkweed can make birds sick if they eat a monarch caterpillar which eats the milkweed....although my Cardinals seem to love the monarch caterpillars! I would guess that other animals could possibly get a little sick from the milkweed if they ate it, also. The milkweed "white sap" has cardenolide glycosides in it which make it poison.
The Asclepias tuberosa is also called Pleurisy Root. It is available for use, but should be taken only when recommended by a qualified health professional. It's easy to guess what it's used for from its name.
I have a Cassia (or Senna--depending on what they're calling it these days) blooming outside my window. It's been attracting a lot of the Yellow Sulphur butterflies. I presume they're laying eggs, so I should have loads more.
I've also had Monarchs, Cabbage Whites, Gulf Frittalaries, Mourning Cloaks and one Swallowtail in my yard this year so far.
Our main host plant for Swallowtails is Fennel which has naturalized in this area. However, it goes dormant for a short time and is just now really getting going again.
Other plants in that family such as Parsley and Anise which are host plants, but don't grow as abundantly here.
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