Elizabeth Vandor - There is no special trick to building a raised bed for a patio. Just build the bottomless frame as described in this article, and set it directly on your patio or deck. A minimum height of 12 inches is sufficient for all kinds of vegetables, and you can even add a trellis to it for pole beans, etc.
I would like to suggest an amazing product line called "gronomics" . They sell the best raised and elevated beds on the market and the great part is that they are completely tool-free assembly. Check them out, they also offer free garden design services and shippnig.
Great article but how do I make a "raised bed" for my patio?
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