Answer: I suggest a bed height of 6 to 12 inches. The higher end of the range is better, especially for shrubs. Make the bed out of a mix of composted bark and either topsoil or sand (the mix should be predominently compost).
Lay some out on your site where you want the beds to go. Mix it in with your native soil to blend the interface between soil types. Then lay more out on top to reach the desired height.
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