Posted: 21/03/2016 at 21:05
I find that clematis need a couple of years to get their feet settled before they take off. Sometimes they fail and disappear but most pop up again after a year or two - after I've binned the labels and forgotten what they were!
I've always planted deep but I'm finding that some clems are just more sensitive to winter cold than others so now I buy them from a pair of brothers who have a nursery about an hour away from here and they advise me on suitable varieties and also label most of their selection with degrees of frost they can take. I no longer buy any that can't cope with -25C.
As long as they get a good, deep root run I find clematis don't care about being planted in full sun or full shade but they do need to be planted with the aspect that suits them best. Some like full sun. Some like shade. Lots of plants are like that - roses, hardy geraniums, Japanese maples......
You just need to get the right plant for the right place and that's easy with google and forums like this.