When to Prune

I live in the northern tier and have a tropical hibiscus(container). I purchased it 2 years ago and the nursery told me it would not make it if it went dormant over the winter. They sold it as annuals.

Last winter I put it in the basement with natural lighting(not much) and water once a month. this summer we have enjoyed a beautiful hibiscus! fuller than the year before. It is so full and now it needs pruning. When should I prune it---now or in the spring? I welcome any pruning suggestion/comments/tips. Thank you.

Since you're going to let it go dormant, you can prune either time. Pruning now will make it a bit easier to keep since it'll be smaller. Pruning it in the Spring is also fine.
Just remember,either way, pruning will delay blooms for about 3 months.
Here's a link with more info: http://www.trop-hibiscus.com/bfertins.html
Barb