My husband brought home two potted plants. They are not blooming(if they do)at this time. They look like short corn stalks with similar wide blade leaves. I live in the chicago area and I had them on the back deck which gets a southwest exposure. The nite time temp dropped to high fifties and some of the leaves turned black. Any clues as to what they are and how to care of them?

Corn plant, sounds like. If the leaves were moist when it got dark, plants can get mold growth pretty quickly; this is why you should never water at night or late before it gets dark. I live in Fl and have seen them grow outside taller than a house. They enjoy indirect sunlight and I water mine once a week.