Please ignore the misleading subject line. I posted this elsewhere, and I think I'm being confusing. I'm going to try to rewrite this so that it's clearer.

We are installing a deck on the back wall of our garage, and we intend to leave square(ish) gaps (cut-outs) in the decking so that we can plant clematis to grow along the wall of the deck. (I've asked other questions about this here--yes the project is moving slowly!) It will be a mix of Huldine and something else, perhaps Jackmanii since it's so reliable.

Here's a drawing of the deck from above, that shows where the cut-outs will be along the wall of the garage:
{{gwi:38882}}

Here's a picture of cut-outs, in case it's not clear what I mean:
{{gwi:38883}}
Just imagine that those gaps are along a wall (back of the garage) and that clematis are planted in them, instead of trees.

I have a question and a problem.

The question is how big the cut-outs need to be for the clematis to grow through. When I look at the bases of the clematis that I have growing around the yard, they don't take up a lot of space. The plan above allows for 10" x 9" holes, which seem like they should be plenty big, but I'm not sure. What do you think? Another possible solution is to have those borders in the pic lift out, so that if we needed we could have bigger holes to tend to the plants.

The problem is that the surface of the deck will be 10" off the ground. I'm assuming we don't want to put the poor clematis plants down that far. So what do we need to do to help them reach the surface. The idea I've had to is to buy plastic planters (like {{gwi:38881}}), cut the bottoms out, and put them in the ground, OR to build wooden boxes. Both of those ideas would bring the ground, and the bases of the clematis, up to the surface of the deck.

I am, however, worried about frost heave and hardiness. We're in upstate NY, where it gets plenty cold.

I hope this is clear. I'm spending a lot of time trying to explain this on another forum.

Any other thoughts or ideas about this? Thanks for any help!

This post was edited by pbl_ge on Sun, Jul 6, 14 at 12:49