Can the wood be exposed on a hugel in a humid climate?

All of my extremely modest hugelkultur knowledge comes from anecdotes and experience in Montana.  A key design feature is to keep all the wood covered to prevent wicking of moisture out of the pile.  I just watched this video by Edible Acres (upstate NY) and Sean has many cases where the wood is exposed.  After years the exposed wood is rotten, broken down and moss/fungi covered.  So, does this mean that for humid climates the wood does not need to be as carefully covered with soil?

I wonder if the very tall/steep hugels at Paul's site have fully rotted wood in them or if they still have structure holding them tall and strong.  Or, by comparison, would a tall/steep hugel in a humid climate that is definitely rotted keep standing?  Assuming it's got plenty of living roots in it of course.

Not needing to keep soil over every bit of wood gives me ideas of hugels where the wood is a framework that can hold a very steep hugel together for years as the roots/plants evolve.  

Edible Acres Video:

I think that the ideal is certainly complete coverage.

But I am not too worried about a log peaking out here or there, because the wood in my hugels is mostly cottonwood and alder; it is going to rot down fast even if left allone on the surface. The wet but mostly above freezing winters help that along.


I think a framework meant for structural purposes is a bit silly unless you are using a rot resistant wood.. anything I was counting on from these logs would be *very* temporary, and it seems much more efficient to plan around a more permanent shape..

And, using a rot resistant wood and having a whack of it exposed might really amplify both the degree and duration of the wicking issue..


The much smaller hugels I built on my parents property a few years ago had converted 99% of the wood to soil in 3 years, and were definitely not holding their shape; I built enclosures of logs and pallets at the 3 year mark as we liked the raised bed effect rather than the ancient grave mound effect.

But... these were used for annuals, so maybe heavily rooted perrenialified hugels would fare better?

I kind of doubt it would help that much, because the logs shrink as they decompose, and the soil settles and washes down...

What are the evaporation rates of topsoil compared to evaporation rates of wood fibers?
Too many variables. What kind of wood? What direction is it oriented? Are both the soil and the wood shaded by plant cover? To what degree is the wood rotten or root-permeable?

I think we all agree that hugels require both soil and some woody plant material, but I don't think a few twigs poking out or some wood surface exposed by erosion is anything to worry about if you have good plant cover.