Above ground vs below ground huglekulturs...

I am fairly new to all of this permaculture stuff, but one thing that I have noticed is that huglekulturs are generally made above ground. I have seen it recommended to build them underground (i.e. dig a hole, fill with wood and dirt, then plant on top) if people have problems with the way the mounds look. However, generally speaking it seems that the above ground approach it considered better. I am wondering why this is. In theory, from the little that I know about huglekultur, it seems like there would be very little difference, but I have a feeling I am missing something. Any help?

Until somebody with practical experience comes along, maybe I can help a little based on my reading.

Aboveground versus buried (wholly or partly) can matter a lot. An aboveground bed intercepts more sunshine than a level/buried one, but it also dries out faster in sun and wind, plus moisture can drain out of it more easily. In wet climates, this can be a good thing; in dry ones, not so much. The conventional wisdom seems to be that if your climate is too hot, too dry, or too windy, you need to bury your beds.

How hot? How dry? How windy? For that, you'll need one of the experts to chime in.

Note this is not an either/or question, but a spectrum. You can dig a shallow hole and bury your woodpile part way, or you can dig a deeper one and bury it completely.

Another reason some prefer above ground hugelkultur berms is that they are adding texture to the land. This can be helpful in areas where wind is an issue. Also, some crops become easier to harvest when raised up from where the harvester is standing.

That's a couple more off the top of my head.

The traditional huglebed is mostly above ground.

Sepp Holzer, in his recipe for building one recommends digging a 1 metre (about 3 feet) deep trench to begin with. He also specifies that it should be tall enough that nobody can walk on it. These specs ensure that it wont get compacted, and there will be a substantial mass of large wood to decompose over many years, as well as a basin for water to collect.

In arid & semi arid regions, most people have found that, while the deep trench is best for acting as a catchment/storage area for the scarce water, the higher mounds are not as beneficial - they do tend to dry out quicker, and often in these climates, we don't need to worry about heating our beds.

While Sepp did not invent the huglemound, he is certainly the one who brought it to the attention of the rest of us. His system puts about one third of it below ground, and two thirds above ground. That seems to work well for him in his Alpine climate. Like everything in permaculture, there is no "one-size-fits-all". Everything must be designed for the climate and needs of the individual.

Thanks for the help, that actually makes a lot of sense. As I start to learn more about permaculture I am starting to realize exactly what you have just said- every place is different.

Hi Nick:

Great question. Dan and John are correct about traditional hugelkultur not being great in really hot, arid places (like Phoenix, where I live) for all the points listed above. (Note I've done in-ground "hugel" style beds and they are fine)

However, in Battle Creek, a traditional above ground huglekultur would probably work out really well.

Dan Boone wrote:How hot? How dry? How windy?... Note this is not an either/or question, but a spectrum.

John Polk wrote:Like everything in permaculture, there is no "one-size-fits-all". Everything must be designed for the climate and needs of the individual.

Those two quotes really get at the essence of the situation! Thanks everyone.

Jen

Above ground did not work for me they dried out too fast. As a beginner I would try various methods and not only the huegelculture then you see what really works for you.

I live in a very dry and windy area. I did an above ground huglekulture my first year here and it did very poorly. This will be the fourth season coming up and I am taking it out. The wind (even though it is protected on two sides by a corner fence) blows off any covering or moisture it receives. The plants struggle and usually end up dead or don't produce any fruit. I did 4 beds last year by burying the huglekulture and it worked very well. In fact, I still had cherry tomatoes going in one bed when I decided to end my season and stop watering. The tomatoes kept producing for a month and a half more with absolutely no rain and my squash leaves were larger than my head when before they were about the size of my hand.

For my area it comes down to one thing. Burying the bed and putting a high border around it keeps the wind off. This is the most important thing I can do. I depends on the area, so you can't say that one way is better than the other. One way just works better than the other given the environment. The best advice I can give from my experience is to try 3 or 4 different styles and see which works best for your given section of land and garden.

I have been experimenting the last year with more "polished" hugel beds and have used both above ground and buried. In areas where I want to absorbs more water I add the underground trenches and may do two or three adjoining. This is smaller scale 1/4 acre Site.
We shall see how all this grows this year. It's already solving the wet site problem but I have much more water channeling to do.

Just joined, been lurking a while, love the website and of course you guys.

Welcome to permies Chris.

That looks similar to what I was thinking for the south (down slope) side of the driveway on a site I am interested in.
Get the water off of the driveway, and into the soil where it will be useful. What better place to push the snow?
I don't want the water/melt-off charging the soil under the driveway, but charging the soils down slope into the vegetation.

Your system looks like it will encourage the feeder roots to spread to their future drip line - right where you want them to go.

I am trying a semi below and above ground huglekultur. I have a L3500 Kabota with a backhoe attachment. I dug out the top soil, which was about six inches or less and then dug a foot or more of pure red clay out of a space 5X12 feet. In this I placed branches, dry leaves, grass and lots of compost from a landscaper. The landscaper wanted to give me what he pulls out because I will use it. Otherwise he had to pay to get rid of it.
Win, win for both of us. So far over the past 6 to 8 months, I have a pile six feet high. I can't wait for spring to plant in the mound.

nice looking beds chris!
I've only had experience with in-ground huglekultur, hand dug in heavy clay!
In hindsight it would have been much better to just build them on top instead of digging them in as there was problems with drainage in
our wet winters.

It probably depends on the soil make-up.

Thanks John and Ma. Sounds like the Waltons. Lol.

John, I have a similar problem on the drive side of the house. Just started building the swales and Hugelkultur mounds. By watching the water on this side over several storms, I realized this is just a sinkhole taking runoff from the house, the drive, and the adjacent property. Need to think about a solution here as there is no where to channel the water. My initial thoughts were that a substantial mound would absorb most of it, and now I think substantial will turn into huge... Sponge action.

Any suggestions on how to treat a low spot on property would be appreciated. I will upload a couple pics. Thanks.

Hmm. Excess water + low spot. Sounds like a good spot for a pond to me.

Pics of drainage issue. Using both above and below ground hugel beds on a terrace to absorb as much water as possible. I think I have to go huge on this mound and swale. Huge is the first syllable of Hugelkultur so that makes sense.

Yeah John, this would be an ideal place for a pond, but the property line is just a couple feet off the ditch. Maybe a small linear pond as an edge. Thanks for pollinating my thoughts on this.

Pond?

12 or more inches of standing water after heavy rain.

Grettings, Chris! I know I'm about dead opposite of what you have climatically but just in a general sense, are there some species of trees that could fit in this area, not disrupt your management on adjacent places, and not mind their roots in water for stretches of time? Willows? Bald cypress ( probably too large but just thinkin' out loud). If a pond isn't practical, there may be some species of plant that would fit the parameters of the site i.e. flooding. I offer this only as food for thought. I like the practical and aesthetic appearance of your hugelbeets around the trees. Good luck with your projects.

A waterlogged low spot is a great place for a rain garden. Basically, getting perennial plants with deep roots, that can tolerate being immersed after rain events will greatly increase the infiltration of that water.

Mike and Julia, thanks for the verification of what I need to look at next. There are several water loving varieties that I look at for seasonal rains like this. I am pretty new here and picked up most knowledge so far from just watching. Don't have all the Permaculture books, but burned a lot of youtube hours learning. Next step plants. Thanks again.

I looked up many water loving trees and perennials and passed that on to the client. Here's an updated photo on how the water is charging back from the ditch as I build deeper buried hugel beds. Now I just need to let it dry out a bit and dig the big swirly ditch. Secret to success, hd shovel head welded to 1-1/4" thick walled galvanized pipe. Cuts, shaves, and digs deep if you can take the weight.

Thanks for this Site. I continually find myself enthralled and learning so much from your experience and knowledge. One shovel at a time...

I have been thinking about this topic a lot as I live in a dry Mediterranean climate. There are so many benefits to an actual mound that I have thought hard on how to perserve this benefit while avoiding the negatives associated with a tall mound in a dry climate. What I have come up with is sunken hugelkulture mounds.

A trench dug 4.5 feet deep, 15 feet wide, and the length of the desired bed would accommodate one 4.5 foot tall bed with the ditch walls angled 45 to 70 degrees acting as additional vertical growing space. This way the edge and increased surface area are perserved but as the top of the mound is just at surface level you get far less drying. My only concern is flooding but perhaps a ditch leading to a pond will solve that problem.

Here is one style that is being put into practice at Wheaton Labs:

you start by laying wood on the ground surface (green represents preexisting grasses) then excavate a trench on each side while building up.

I prefer to start with a 3-ft deep trench then use wood and the previously excavated soil to build.  We installed about 8 long hugels between 2015 & 2017 and they have not been watered (by humans) since 2018 and everything is still growing - roses, pest-deterrent plants, etc.  

Two suggestions for however you choose to build Hugelkultur:
1. when working above ground put the wood perpendicular to the run of the hugel (the image indicates using long logs running the length of the hugel)
2. ALWAYS have soil in contact with each piece of wood and AVOID stacking wood in a pile then add soil

I like the trench style as I think it catches and stores water better than the start-on-the-ground and build up style.

I've built a long narrow one along the edge of the road with dead oaks a few years back [They have the wilt and should not be sold, even for firewood.]
I got it on the top of the ground, piled up between 2 lines of poles. Long story short, it was about 4ft wide and 6 to 7 ft. high. Oak does not deteriorate very fast, even when it has the wilt. It is down to 4 ft. now but it still gives us a little break against the wind that howls in the winter. It started as a great snow trap. In our sandbox, that is important It gives shelter to a lot of wild life. Squirrels, partridges and smaller birds.
It was not a waste: Deer don't like to jump if they don't have to, so they go to the one end to get deeper into our little forest. During the hunting season, we can usually bag a deer. [they always come around the north side of that... whatever I built there.. I would have to pile dirt on it to make it a real hügelkultur mound but I'm loath to import soil and that is pretty much what we'd have to do. My sandbox has less than 2" of top soil. Stealing it from some place else on our property does not give me any advantage as that little bit of top soil would then be missing from there! not to mention the additional work.
The oaks are still dying, they still have the wilt, so we still can't sell them. I walk in the woods foraging for mushrooms [and now we grow a few. The barrier prevents the deer from eating them all.] The branches broke from their weight and the snow and rain, It is now pretty solid wood and you can't see through it, so it will eventually be a hügelkultur. I think the squirrels are planting it for me. Some young oaks are coming through, [I have no hope that they won't get sick though. Perhaps some will survive the wilt and acquire a resistance, who knows?] and wild cherries. On the leeward side, we installed a stump with maitake and we are starting to get this hen of the woods. I hope we get many more.
It was work piling all that wood on about 100 ft. but not as much as a real hügelkultur mound would be. We still get many rewards from it, plus we are effectively dealing with dead oaks that were not going to give us acorns anyway, making room for other trees [sugar maple is a favorite of mine]. All in all, I'm happy with the results, even if it is not a hügelkultur mound in the strict sense of the term. I could make it more of a hügelkultur mound by dropping all green refuse on top... but my chickens enjoy my green "waste".