I built and planted a strawberry tower this weekend.
I drilled 2" holes with a hole saw and staggered them along all four sides. I buried it about a foot deep. I took a 3/4" pipe and drilled small holes in it and placed it down the center of the post to use for watering (the cap comes off to get to the pipe). I added soil from the garden and as I came to each hole I transplanted a wandering strawberry out of my garden path into each hole. I'll let you know how it works this year!