We have a small cottage on Keats Island in Howe Sound, on the north side. There's a large quantity of blackberry that's smothered much of whatever used to be there. As a long-term project we want to get rid of as much of the blackberry as we can and replace with appropriate native shrubs and ground cover plants. Which plants would you suggest? The slope is fairly steep in parts. I have lots of smilacina racemosa from my house and could easily transplant the extras, but it's a bit of a thug and I'm wary of introducing another problem (not that it would be as bad as the blackberry).