can kill them. Do not buy this milkweed for your butterfly garden if you live in Florida. These milkweeds are marketed through big box nurseries and the like.
To help the Monarch butterfly in Florida homeowners need to be providers for the essential milkweed the caterpillars need to live. Here is a website that I found helpful. I plan on getting some seeds soon to grow milkweed.
** both images are from wikipedia