I have cut tree branches in the bottom of one raised bed (Hugelkultur), and that's the bed where my summer squash all perished by fungus. So I'm thinking I should remove the wood, and just add some perlite to help the soil retain moisture instead. We are in a high fire danger zone, so any burning of green waste is illegal: I'm not making any biochar in the foreseeable future.

Educating anyone benefits everyone.