Cobaea scandens (a/k/a Cup and Saucer Vine or Cathedral Bells)

After seeing pictures of Cobaea scandens online last year, I decided I had to have one. I bought a second-year plant at a local farmers market and planted it this June. It grew amazingly fast once the weather finally warmed up in July, but it didn't bloom until mid-to-late September. Now, though, it's beautiful, just in time for frost season. The person I bought it from told me it's hardy to 26F, so I plan to mulch it heavily with straw and hope for the best. I've been trying to take cuttings from it as a bit of insurance, but so far I can't get any of them to root in either water or potting soil. If anyone knows how to root cuttings from this plant, please let me know.

This picture was taken this morning.