Hi Susan, saw this link and it gives good info about your plant:
http://looking-at-plants.com/p...
Reading through it, it seems better to do your trimming around Spring time. Also says if you do some pruning, it will encourage the plant to branch out, since it does tend to go leggy. I do not grow that type of croton, but the croton I have, I find it loves daily misting on the leaves in my area, maybe because our place is so dry during summer. My croton also drops some leaves when it transitions from outdoors to indoors during winter, and it just grows back new leaves outdoors when our temperatures are back in the low 70-80's range.