Posted: 30/05/2017 at 17:42
Climbing hydrangeas get massive. They cover house walls. Have you got one of those and a honeysuckle in that same bed? Montanas too - they're perfect for covering sheds, garages etc, but you need to think ahead and consider the sizes of the climbers you plant. You can't keep pruning them into a smaller size and get the right results from them.
Clematis need a good amount of water and decent soil - you need to consider that if you build a container of any kind, and anything else you plant will need to enjoy the same conditions. For instance, you can't plant something that likes really free draining, poor soil in the same area as a clematis. I wouldn't rush into a decision - take your time to research the plants.
Re lining- yes I would - especially if the area doesn''t get lots of rain directly into it. Raised beds dry out quicker. That tree will block a lot of wet stuff depending on the direction your weather comes in. You'll also need to use a soil based medium in it, and some rotted manure will also benefit any planting. Mulcing will also help to retain moisture. This is when knowing your own site and conditions influences your plant choices, and saves making expensive mistakes!