These are so pretty! I started them indoors 2 years ago. Must have been too late because I only got blooms in August.

Thank you. I had good luck with growing Ipomoea purpurea indoors during the winter. I give them short day type lighting to simulate the shortening days the plants experience during late summer. I never grew this species indoors during the winter before. Usually I grow Ipomoea nil, which also flowers up quickly with short-day photoperiod. So it was an experiment that was successful. Here is the plant that I grew under the grow lights.

Notice I am growing it in an 8 ounce yogurt cup. I got lucky with it growing it this way, but it's more labor intensive because I have to water it every day.

I remember that one issue I had was that they quickly grew indoors and I had nothing to stake them. Do you know if it's ok to prune it while it's indoors, then let it go wild once it's outside?

Snipping the tips of the vines will slow down growth of the vine in one direction; lateral vines will be produced which will produce a bushier plant and possibly make more flowers.

Here is one that is currently blooming.