I finally had a bright idea to maximize more space in the garden. The sloping edge of the former pond has remained hard packed clay pierced only by the fiercest weeds, from the rim to the cultivated floor. I decided if I put in a short wall, then I can create another tier of usable garden beds by filling it in with readily available biomass (old hay, horse crap, etc). It may easily double the growable area of my pond garden.
I can even hide small branches in there, now that I know about hugelculture.
All I have to do is dump matter in the new terrace and the soil will build itself, probably ready for next year. Well, not “all” I have to do…first I have to remove barrowfuls of rocks, most of which got thrown to the edges in the original garden-building. It is laborious, but certainly not as hard as trying to break, aerate, and ameliorate that dry, dead, dense “bedrock” of clay.