KMZ Landscape Design there are just 4x4 posts with 1x4 wrapping the outside. you can see through the gaps to allow air and glimpses out or in. all the wood is cedar.
The project is in Vancouver British Columbia, so while we do get some freezing days it is nothing like Detroit. I use dot work in Torono - if I was building this there I would use either a 4x4 or 6x6 post with 2 x 4 or 2x6 boards to wrap around. In Toronto everyone wanted the wood stained so I'd find a nice opaque stain to put on - most likely to match the house or the trim on the house. Whichever looks best.

nicksalisbury I really like the wrapped corners and ends. What prevents the wood from separating at the corner joint as the wood shrinks from drying over time? What kind of fastener was used here? Is the channel siding mitered? Is it working over time?