"Geoff" wrote in message
...
Your best bet is to use gravel board which is about an inch thick, 6
inches wide and chemically treated. My raised beds are are made of two
such boards the longer sides being attached to 3 X3 inch fence posts at
the ends using coach screws. The shorter sides are likewise screwed to
the 3 X 3 which are inside the corners of the bed.

Geoff


Thats exactly how we did ours, but with three planks
high...................too high for dog to water the veg.......which no one
will eat if he does manage to sprinkle them. We added some knobs on top of
the posts. Indoor wooden knobs cos we couldn't find the right size outdoor
ones. All painted with cuprinol paint.