Last year's 100% deathrate of my Swan plants was a disaster, so I've completely replanted and I'm now researching 'poverty' foods just in case. I will try to get Tweedia (I'm in Australia so buying overseas seeds is oftem difficult) but I also noticed a mention of the Pepper tree (Schinus molle).
This is readily available. Has anyone tried to raise Monarchs on it? I have used it in the past for Stick insects, which liked it but it tended to gum up their mouth parts. Handy in an emergency though.
I have a huge, proliferating pepper tree in the paddock. If hungry monarch caterpillars will eat it I will be very happy. Lots of Asc. fructicosa germinated, but my attempts to germinate incarnata, syracusa, speciosa, rotundifolia and curassavica were pretty woeful.
Fortunately very few butterflies have arrived so far. It sometimes happens like this, - then there are still caterpillars around when winter sets in.