Clematis: fairly new jackmani, 1 by crockny

crockny wrote:
This is the second year I've had it -- the first year I grew it under a rose bush but there were other bushes shading it out and it didn't grow -- I thought I'd lost it -- last year I put it out in the sun with mulch around the roots ... it was just barely alive ... this year it's coming up on a single stem and looks pretty good ... but I didn't prune it back in the spring like I hear you should ... I'm thinking it's too late to prune it and since it's been struggling I should just leave it alone ... what do you experienced clematis growers think?

Here's a picture - not a clematis but just something that's growing now in my Hudson Valley garden ...