I want to make one of the fence sections around my yard into a gate.
They are regular spaced vertical planks of cedar on three horizontal
planks, and about 8 feet wide and 6 high.

I was considering cutting in half down the middle, putting a couple of
diagonals (one in each side). And then hinging the edges. The posts are
solid and concreted in fine.

Does this sound like a decent plan? I'm concerned about the thing
sagging. I don't want any latch in the middle, so I'll put in a
castle-style plank that can be lifted or rotated out of the way.

Thanks for any tips if anyone has done such a thing.

Dean