I wish I could remember if mine bloomed in its first few years or not (I suspect it did just fine year two). I just wanted to say that once it does bloom it is prolific and the best part is that it smells lovely, something you don't get with most other clematis varieties.

I bought one, had it in a gallon pot over the winter, but it died of cold. I grew other clems in gallon pots left outside all winter and they did fine.

I've grown it for a number of years. It probably took until its third year before it bloomed very heavily. But it does produce a mass of slightly fragrant late summer blooms. I also grow xtriternata 'Rubromarginata', which is very similar and holds some similar parentage. I actually prefer that one over SSL

My triternata bloomed for the first time this year. Not many blooms but very nice to see some. They were not as tiny as Sweet Autumn Clematis I think... slightly bigger, with nice purply red margins and a little fragrance. For a small blooming stunning clem I really liked Avant Garde this year. Once it gets some size it looks great. Mine has been a trouper in a big pot , not fussy all summer.