Is it a fence, a trellis, or both? It's meant to be a visual backdrop to one side of the backyard and it's meant to support climbing plants as well. I tried to design something that could do both. I used cedar so that it would last and I wanted a wood that would weather to a natural gray.
I laid out the posts in the driveway at the distance apart I'd put them in so that I could accurately create the curved top rail of the fence.
This is one end of a giant compass. I attached mason line to a stake 24 feet away to draw an arc on the 2 x 12 cedar board.
I used a hand held jig saw to cut along the scribed arc.
I used a router to round the edges and then sanded the whole thing down. The tenon at the end will be inserted into a mortised post.
Finished top rails.
It took some searching to find a can of the wood treatment for ground contact but my local hardware store ordered some for me. It's easy to find pressure treated lumber, but I wanted the posts to weather like the rest of the fence so I only wanted the part I buried to be treated. (The treatment comes up about 4 inches above ground.) I only needed enough for three posts so I've a fair amount of wood preservative left over. Hmmm... I'll need to build more outdoor things.
The dirt excavated for the posts was mostly black top soil all the way down for the four foot depth I dug for the posts. It's rich soil. I suspect this is one reason why the plants in the backyard are generally pretty happy. I used a tarp to pile the soil on so that I could more easily keep it from getting in the lawn and in the mulch. If there's not too much, you can also move soil this way by just dragging the tarp.
There was one exception. About two feet down I ran into part of an old structure on the middle post. It required a jack hammer to break it up. I rented one and in less than 20 minutes I was through the buried concrete. Makes one wonder what was there. Edge of the foundation for an old outhouse? Is this why my soil is so rich? No idea.
Posts go in.
First rails in place. I used a rope between the posts and twisted it to pull the two posts tightly together after placing the tenons in the mortises I'd made in the posts. With the rope in place I used stainless steel screws to anchor the rails to the posts.
I just used 1x1s for the slats and attached them with stainless steel screws.
All parts in place.
I waited to the end to cut the posts to height and put copper caps on the end posts. A birdhouse will go on the middle post.