Raised bed height

[schill93]

I live in the Las Vegas desert where temperatures allow you to cook your vegetables while they grow, similar to Phoenix, Az.. I will be building raised beds for the 2017 season and wondered about height. Our soil here is clay and hard as rock with very poor drainage. It is also very alkaline.

Since moving here I have noted that planting anything in 15 gallon containers that are 16" tall did better than those in my 11" tall Earthbox"s with similar amount of mix. Which leads me to believe that the same would apply to raised beds.

I know many of you have rich soil and plant roots will benefit from extending down into it. In my case, not so much. Common wisdom seems to dictate that 12" should be adequate. However, I question that wisdom here.

I realize that anyone not living in such conditions may not be able to relate to my circumstances. But who knows. Thought I should ask in case anyone has had experience with it.