On Tuesday, October 31, 2017 at 9:22:43 AM UTC, Martin Brown wrote:

Some of each. Ash still has the mineral content but no bulk. In an ideal
world you want the heap to get upto 60-70C internally and stay there
until stuff has been digested. A mix of grass and some woody bits helps
keep things under control. A hot heap will eat quite woody prunings.

Thanks for your input, Martin. So it *was* ash! I think I'll continue with my hole-poking method after reading your reply.

Al