“We buried two 4×4 treated wood posts into the ground with cement to help anchor them.
For the top three planters, we built a frame from two 1″ x 6″ x 12′ and two 1″ x 6″ x 4″ cuts of untreated cedar
For the bottom planter, we used 8″ boards instead. (If we were to rebuild this wall, I would use all 8″ wide boards because it gives more room for dirt and dries out less quickly.)
Additional 4″ wide cuts were used to close each section of planter by the support posts. We did not want the treated support post wood to leach any non-food safe chemicals into the dirt.
The remaining 4″ wide cuts were nailed into the bottom of each box at staggered intervals in order to provide support.
Each planter was lined with window screen before being filled with dirt and plants. One alternative build would be to make wider planter shelves and set plastic/ceramic planters or pots inside (instead of window screen and dirt)…”
