I'm pretty new to gardening. I live in NYC and started a rooftop garden this past summer. I've got a beautiful rose bush, some geraniums, impatiens, and the beginnings of some morning glory vines. They've all done well so far.

I also had a small Japanese Honeysuckle plant that was doing pretty well in a container that seemed to be big enough for the time being. Then, about 8-10 days ago, I noticed some of the leaves yellowing. I thought maybe I was watering too often, now that it'd begun to get cooler outside. Watering every few days didn't help - more and more leaves were yellowing and wilting . I didn't see any bugs or mildew, and so I didn't want to use any kind of spray unnecessarily. I continued watering it whenever the soil got too dry. But now, many of the leaves have died and fallen off.

Did I do something wrong? I did use some Miracle Grow flower food on it a few weeks before I noticed the initial problem. Could that be it? Did I kill the plant? Help, please!