Spec's Garden - I am thinking of a complete change

The parts of the trunk are about 2ft.across and cut into 2.5 ft. lengths and the branches about 8ft. Various thickness of 3 to 6in. along with a lot of thinner branches, and if they are covered by at least 18 inches of soil I don't think woodlice would be any problem, though I don't think they do any damage to fresh vegetation anyway, I believe that with hugelkulture it's the second year onwards that the necessity for watering stops