Back in 2014 I posted a thread showing the 'tree' structures RBG (Royal Botanical Gardens in Burlington Ontario) had installed for clematises. I'm sure I updated it last year but can't find the thread - it might be in the Perennials forum where I hang out most of the time.... We dropped by the area this afternoon to see how they were doing. Some of the clematises have died completely while other are thriving - and some are in-between.

I really liked this Kermesina clematis (I can't remember what the blue one in the background is....)

Huldine was unmistakable - and very vigorous of course.

Duchess of Albany was one of the tallest ones - the 'tree' structures would obviously have to be much larger to retain the 'tree' look once vigorous clematises reach the top.

I wonder if RBG will be preparing/posting a report on which clematises were planted and how they did....?