Finished product first! This is about 4 weeks after planting. Closest middle hexagon holds sage, thyme, basil, cilantro, and lemon verbena. Next to the left holds arugula and brussel sprouts. Behind that holds more brussel sprouts, bok choy, green onions, shallots, and fennel. Right of that holds carrots and sweet onions. Right of that holds potatoes. 

Got a bunch of cheap 2' cedar leftovers from a local lumber yard 

Profile of each board type you need to cut. In total I needed 22 of the bottom board, 18 of second from bottom, 60 of third from bottom, and 54 of top. Top 3 boards each form panels that make up sides of garden box while bottom board forms post that holds each panel together. 

All boards cut down to size. 

6 boards of a given type with a post form an assembled panel. 

All panels assembled. 

I almost messed this part up -- half of the parallelogram-shaped panels should face one way and half should face the other way. 

All assembled! I was really surprised how easily everything fit together given how little measuring I did. 

On planting day.

4 weeks later (potatoes still haven't shown up in the far right hexagon, I'm beginning to get suspicious). Cost was about $130 for the wood, $40 for the screws, $60 for compost and $40 for a truck to haul the compost. Total cost $270.