Thanks David,
Just the answer I was looking for and from someone who has done this!
I plan on using PT wood...
Couple of other questions:
How deep did you dig ie is each 2x12 buried to the surface?
I'm thinking burying and leaving a couple of inches exposed
Anything else done to the wood...or just use back fill and fence to
hold in place?
Since I have a grading going from 6 to 24, should I use 2x12 by 8 feet
long?
Did you connect boards?
Thanks for your quick response.