Which Milkweed did you plant? And are they potbound?
The best Milkweed for you in your zone is probably Tropical Milkweed, or Whitevine if you're in Florida. Northern cold loving species like Tuberosa, Syriaca and Incarnata may suffer too far South. They need a really cold winter.
Potbound plants will wilt often unless the roots are spread out a little and allowed to grow into the soil instead of around in a circle. You can even cut the bottom half inch or so if necessary.
Hope this helps...

John

Hi John!

Thanks for your reply. I did plant tropical milkweed. I purchased 3 of them from a garden center in and transferred them to a large 36" diameter planter.

I'll try giving the roots a trim, but I'm curious if I have them in an insufficient location. I placed them in a spot where they have indirect sunlight most of the day with a few hours of evening sun. I was afraid of burning them with the heat and high UV index, but now I'm wondering if they aren't getting enough sunlight.

Any ideas out there?

They definitely need full sunlight for at least 8 hours a day for optimal growth, bloom and nutritional value. Morning sun is best, with some shade during the hot hours, and moderate watering.

John

Hi John!

Thanks for your reply. I did plant tropical milkweed. I purchased 3 of them from a garden center in and transferred them to a large 36" diameter planter.

I'll try giving the roots a trim, but I'm curious if I have them in an insufficient location. I placed them in a spot where they have indirect sunlight most of the day with a few hours of evening sun. I was afraid of burning them with the heat and high UV index, but now I'm wondering if they aren't getting enough sunlight.

Any ideas out there?

Most plants will look wilted during the heat of the day and then perk up after the sun goes down. That is their way of dealing with the heat. Give them some time to recover from transplanting. Tropicals are pretty easy and that is why I love them. I wrote this on container gardening. You maybe able to use some of the suggestions. See the link below.

Here is a link that might be useful: Container Gardening for Monarchs

In the heat of the summer, I water the potted plants daily and provide them some shade from about noon on. Mine are flourishing. I did have spider mites attack a flat of tropical milkweed I had purchased and they did manage to kill several of them before I clued in. Try checking under the leaves for signs of webbing or mites (teeny tiny moving dots about the size of this . ) If you have the, rinse, rinse, rinse the leaves. A few treatments of insecticidal soap too (as long as you don't have any eggs or hatchlings on the plants.)

~Laura