Yellowing and rusty leaves

[DebDavis]

I'm new to forum as well as butterfly gardening. Please help. I had a beautiful milkweed garden going, still getting a lot of monarchs, but now many of my plants are turning yellow and sort of rusty. Some others are just getting yellow and wilting.

I've also noticed that other young plants I started from seeds are just drying up and dying. They were well on their way and doing fine. It has been dry here in South Florida, but I've been watering them as much as I can, and I thought they were drought tolerant as well. I'm wondering if I over fertilized or is it something else?

I have a photo here:

[Mona Miller]

http://www.mobot.org/gardeninghelp/Plan ... urassavica
Problems Associated with Asclepias curassavica

My seedlings are dying. I thought it was damping off. Too much water.