Hi Nancy, Kimberly here from landscape solutions for you. Thank you for asking what plants you could do in containers in Chicago during the summer months.
Chicago can get warm and humid and there are few that come to mind.
1. Ginger - it should do well in a container in your area. I received a variegated Ginger plant bulb from a friend that went to Hawaii. I put it into a container and it grew well. I decided to put in out in my zone seven last summer, and with the acid base soil, it did terrible. I have had it in the house for over a year now and doing great and is thriving at over six feet. You may be able to have these tropical plants outside during the summer, and inside during the cold winter months.
2. Fatsia - great big leaf plant -
3. Angel Trumpet - great looking flowers -
4. Hibiscus - one of my favorites that will do well in a container -
5. Mandevilla - gorgeous tropical plant -
6. Jasmine - great plant and you can use a small trellis in the container -
7. Sago Palm - smaller palm tree and should do fine in your climate during the summer months. Protect from the winter cold.
All of these are some possibilities for you. If you haven't had a chance check out the tropics section here on the Web site. You may get some more ideas for some tropical plants.
I hope this has helped you some and best of luck to you with your tropical look. Thanks again for asking the question here at landscape solutions for you. Hope your day is going well. Kimberly