Solanum Glasnevin - Chilean Potato vine

I have been growing a Solanum in my garden for about 5 years now. It always produces such lovely, long lasting flowers throughout the summer.

The trouble now is that it is about 4 metres high and all the flowers are right at the top of the plant with nothing on the lower branches. It looks pretty straggly. Can anyone advise me on whether hard pruning (maybe down to 1 metre off the ground), would kill it or would I get new growth starting again and what time of year should I do it. I presume now (end of May, is too late for hard pruning) or what else should I do ?

Advice would be welcome

 

I'd do it in February

 

I had one in Bucks ... I would do it now. Sorry, my pics are actually photos under the bed,