Comment by sholladay
12 hours ago
The “butterfly bush” is native to China. Milkweed is native to North America.
Milkweed is the only one that can feed the Monarch at all stages of its life, from larva to caterpillar to butterfly. When people plant butterfly bushes, it “tricks” the butterfly (or at least crowds out better options) into laying eggs where the larvae will ultimately die of starvation.
There are many species of milkweed and they're not all the same to the butterflies. Try to grow the ones that are native to your area.
https://en.wikipedia.org/wiki/Asclepias#Ecology
https://www.growmilkweedplants.com/map