"Peter Hemmings" wrote
I have a Wisley Cream clematis on a back westerly facing fence.
I've had it about four years, after 2 years without flowering I said to
it that if no flowers on the 3rd year I would pull it out!!
Last spring I had about 10 flowers and this year I have had a lot of
growth with about 20 flowers!!
I know this species can be a problem, but as it has made an effort I
would like to keep it longer!
Should I cut it back now (flowers just finishing) or wait till danger of
frost is over?
Do I cut hard back or just trimmed (it has got rather rampant).
Also is there any way to encourage flowering?

IMHO and with apologies to the hybridiser, 'Wisley Cream' is a coarse
plant. It's a lank grower, tends to be an unreliable flowerer and has
none of the freckling of the flowers that is such a charming feature of
the species. I'm not sure that anything you try will necessarily improve
it.

I much prefer C. cirrhosa ssp. balearica, which is an altogether more
attractive and well behaved plant. The flowers are similar to C. cirrhosa
(with the reddish "freckles"), and the foliage is finely cut, with a
bronze tinge. It flowers December to March, is perfectly hardy throughout
most of the UK and received an AGM in January 1974. Mine tends to stop
growing and can even look a little sickly in the hot weather of high
summer, but this is perfectly normal. When the cooler, wetter weather
arrives in autumn, it freshens itself up and starts shooting away in
preparation for its regular winter display.

- Tom.