Here are some thoughts about a revision to my raised bed, now in the final stages of becoming a Hugelkulture garden!
I accomplished this by digging out the center of the raised bed and filling it with lengths of the trunk and branches from a dying Redbud tree. Once the branches begin to decompose, they become a prime underpinning for an organic garden, but that will take some time, so in the meantime, I am packing the timbers down and filling the spaces with mulch so the process begins faster and holes don’t develop once I have covered the wood with good garden soil.
You could speed up the process by using Biochar as a kick-start. That would mean partially burning the wood and then covering it with earth, creating charred wood, which releases its nutrients faster, when mixed with organic soil and compost.