Posted: 18/07/2015 at 13:52
Poppy, very quickly is the answer.
I cut a tall cordy hard back every few years. Two years, maybe 3, I cut a single stemmed, 15' specimen back to the ground. It sprouted the next growing spring from an autumn cut. It is now 7' plus with 3 selected shoots.
You can do this, i.e.., select how many and where you want your shoots by rubbing out those not required.
Sorry just realised you ssked about flowers, didnt you? They dont always flower so no definite answer after all. But they will do