I built a similar planter, four rows high, and dug out a footer trench about
14" wide and 6" deep, then built 1x4 forms to result in concrete cross
section of 4x12", with a compacted gravel or sand base, and a pair of 1/4 or
3/8 inch rebars running the length of the footer. Rented an electric mixer,
and mixed concrete by the wheelbarrow load, to fill the forms. This was for
a swampy/sandy area. More durable soil may take less width of footer, I
don't know. I also put weep holes (just skipped the edge mortar) between
every 4th brick, on the bottom row, to assure drainage
There are also good resources at home improvement stores in the do it
yourself magazine and book sections, that have specific suggestions for how
to do footers, etc. Look under brick/masonry projects, and garden/patio
plan books. Also lots of info on the web via google.
Also, many sources on the net, via google, e.g.
http://chambers-tx.tamu.edu/publications/B6102.pdf


I want to put a simple raised planter around the perimeter of my back yard
that will be built of bricks maybe, say, three or four rows high (about 12
inches). What do I need to lay down on the soil as (or under) my first
layer? Anything special?

- Magnusfarce