An internet search will yield a plethora of different designs. Most of them are round but ours we made rectangularish to even better utilize space in our limited area of the side yard.
The goals for our planting bed were simple - we wanted it slightly raised to make it easier to work in and because the bed would sit on the north side of our house where the sun doesn't shine as much a higher bed would be able to receive more sun. We also wanted to utilize mostly natural and local materials.
We built it using local roundish river rocks, sand, clay earth from our yard and a small amount of cement. The mix ratio was 2 parts sand, 2 parts clay, and 1 part Portland cement. This ratio provided a nice consistency that balanced the use of natural materials with a final product that would withstand the elements of weather for many many years.
BEFORE AND AFTER
BEFORE AND AFTER
https://www.facebook.com/Permasystems/