Posted: 23/07/2015 at 19:13
I have used this on the nursery with good results in the past, Dave.
It is not a ' risky strategy ' to prune clematis hard back at this time, or any other time, of year.
On an almost daily basis any weak looking or single stemmed clematis are chopped hard back here, some of the material is used for cuttings.
I have just butchered back a large batch of potted clematis Purpurea Plena Elegans this afternoon, in another month or so they will be sturdier, bushier plants.