Hi Jay
There are lots of different ways of using the hugelkultur technique to build beds. I live on an island that is mostly sand, and have hot dry summers and wet mild winters, so I opted for digging trenches and filling with
wood and debris so it is just above ground level. I think that unless you are building a HUGE hugelkultur, digging trenches and burying the wood will yield the best results in a hot dry climate. In the winter, the
water flows into the trench and the wood soaks up the water which will help to keep the beds hydrated in the hot summer. I think that the beds really hit their stride in the third year, when the wood has become soaked with water, and is breaking down and releasing nutrients to the plants. I don't think you need to worry about the trench becoming a moat. The water will soak into the wood, and also begin to soak in and soften the surrounding soil, as well as begin to bring it back to life.
My beds are only in their first year, but are performing beautifully. As for your question about using crappy soil, well, we don't have any soil at all. So my beds are built using not only logs and sticks, but also wood chips, and year-old grass/leaves/weeds,
compost, and some sand. There is no soil in my beds at all, except what went in with the transplants. So, I think that no matter how crappy your soil is, if you are also adding in a variety of greens as well as
carbon in the form of wood, sticks or wood chips, it will work well. I think they work best if you build them and let them go through a wet season to soak up water, but we finished ours in June this year, and I planted right into them.
I haven't seen the video you referred to, but I have been studying the subject for the last couple of years, so when I built my beds I used what I had available, and it's worked out great so far. I have added some amendments to the beds, to compensate for the lack of soil - some minerals in the form of rock dust, seaweed, lime and other goodies to help create a good growing medium for my plants. And they are very happy. You will probably want to do a soil test to see what your soil might need in the form of amendments.
I'm sure others will join the conversation with more examples and ideas; I wanted to share what has worked for me, and to let you know that I think this technique leaves a lot of room for people to use the resources they have available, and not follow a strict 'recipe'. If you find that you are unable to dig deep trenches, even wood buried in shallow ditches will help. And if you can't dig trenches at all, then make sure your hugel piles are large
enough to hold a good deal of water, and you soak them really well, or they will dry out quickly in a dry summer. You'd have to water the heck out of them. But if they are quite wide and tall, they will hold much more water.
That's just my two cent's worth.
Hope it helps.
Cheers
Tracy