My mother in law grew them in New Orleans and they did take some shade. They reseed easily (and the seeds are very easy to collect), but plant where they won't be invading other plants.

half and half shade and sun, in an open area just for them,,, they reseed and drop and u get more plants and the wind blows the seeds and if u pick the seeds u can share

The area I had mine in had full sun in the morning until about noon, but no direct sun from then on and they did beautifully.

Remember also, if they get too tall you can cut them back to a better height and they will fill in beautufilly.

They're not kidding about the seeds. Here in Tennessee things are hilly... so I had trouble with the seeds rolling down hill and spreading into areas where I didn't want them. But they're easy enough to simply pull up and throw away, when they're first coming up. Each season I would find myself collecting seeds and would easily gather at least 3-4 cups worth to share or toss out the car window into vacant lots in the neighborhood.

The scent was wonderful! I hope you enjoy yours as much as we did ours.

We gave ours up this year in a redesign of our patio/deck area. I had a problem with aphids attacking one of my crape myrtles and thought that the four o'clocks were drawing them to the area or at least giving them a good home... so I decided to do away with them, for now.

Good luck with them!