Posting this as a goal for myself. The plan for the future blackberry bed. Do this now, plant bare root in the early spring. Finger crossed. 

Hugelkultur (hoo-gul-culture), is a German horticulture method to make raised beds that use rotting wood to provide nutrients for fruits, vegetables, and herbs. This permaculture technique allows gardeners to replicate nutrient cycles that occur in natural forest areas. By layering different materials (compost, mulch, fertilizer, etc.) on top of the wood to provide additional nutrients, gardeners are able to create a self-sustaining raised bed.