George
We prune all 100+ of the Clems every year, ranging from a hard prune to just a light tidy up.
Take Clematis texensis Dutchess of Albany
It looks fairly delicate don't you think.
A group 3 so a hard prune down to about 18 inches above ground end of February time.
It will sit there sulking for a couple of weeks, but it is really just gathering itself for the thrust upwards.
Today it's strongest shoots are at 5 foot tall, and it will continue upwards and outward above the 6 foot fence panel and onto a bean net which is attached to the top of the neighbours 14 foot ish high leylandii hedge (which we cut our side and as far as I can reach over the top every year)
Not content with reaching the top it will then dissapear from sight heading next door.
Lyn does cut out the growing tips, and also complete shoots in an attempt to control it.
It killed a pretty strong shrub I can't remember the name of one year, that it used for a support, and even tries to kill the leylandii, leaving brown patches of foilage.
Just think how much stronger it would be if it's roots were not at the base of the hedge, more water and nourishment would be available to it.
I guess we have had the Dutchess in the garden for about 8 years now, every year it has grown stronger.
The flowering time is quite long, and the flowers are nice.
Malcolm