I just planted the swamp milkweeds this spring. They were tiny little seedlings and now just a foot and a half tall and I already have monarchs! I feel like I should be standing guard over them.
Enjoy your many chrysalises if you have a door or other structure nearby. Used to have butterfly bush and it was a sight to see every season when it was swarmed with these fellas. Then they post up in a corner or door jamb and you get to watch em change real time. I’d recommend prepping a time lapse setup if you are so inclined.