As stated in my previous post on the subject, my hugelkultur terrace needed more stuff. The level hadn't dropped very much, but enough to be noticeable if you really looked. No doubt this process will continue as everything rots down, so it'll need feeding regularly, I expect.
Over the course of a couple of months, starting in December when I thought the plants might be going dormant for the winter, I added extra stuff to the terrace. I added lots of bark from our firewood (it holds water, so if the logs have been rained on, that'll be the wettest bit), bracken, all sorts of straw and woody bits from the garden, hedge trimmings, and lots of oak leaves. The result is that my once-green terrace is again brown.
I now wait anxiously to see how many of the plants make it up through that layer. I'm sure the buttercups and, unfortunately, the grass will get through; I hope the speedwell and clover make it, too. At worst, I'll have a buttercup meadow, which really isn't that bad, is it?