The Hugelkultur Question

hugelkultur
A debate broke out at the Root Simple headquarters this past weekend over hugelkultur.

Hugelkultur is the most talked about concept in the permaculuture world. The idea with hugelkultur is that you mound or bury logs in compost and plant in it. Proponents contend that the logs break down and become open fungal pathways to store water and nutrients.

Kelly suggested we take an unused raised bed in our front yard and try an at-grade hugelkultur experiment (mounding in our dry climate seems like a bad idea, especially given our current drought). I balked at the amount of digging that would be involved. Kelly suggested that we should try it since we had little to lose and we’re supposed to be experimenting with garden ideas for the sake of our readers. I, again, thought about all the digging and the excess soil that would have to be carried down the staircase.

Then I had a change of heart. We should be experimenting, I thought. And we have a pile of wood.

But, like a gardening version of Hamlet, I started waffling again. I decided to post the hugelkultur question to the Garden Professor’s Facebook page. One of those horticulture professors, Linda Chalker-Scott is someone who I seek out when writing a magazine article. A civil discussion ensued on that Facebook page, proving that Facebook is good for something other than angry political screeds and cat videos. A summary of some of the points made:

  • There is no peer reviewed research on hugelkultur.
  • The concept seems to date back only to 2007 or so, most likely to Sepp Holzer.
  • Chalker-Scott suggested that you could get the same benefits with surface mulch with a lot less effort. See a previous Root Simple blog post for the reasons why mulch does many of the same things as hugelkultur.
  • Someone pointed out that subsidence in a hugelkultur bed might be bad for trees, though many use hugelkultur just for vegetables.
  • I pointed out that nature mulches but does not hugelkultur (except maybe in the case of floods).
  • Relieved that I would not need to dig, I chimed in that I thought that hugelkultur would rob soil of nitrogen as the carbon material broke down.
  • A hugelkultur supporter countered that large logs would not rob soil of nitrogen due to the surface to area ratio.
  • The conversation concluded with a back and forth on mulch vs. hugelkultur and the benefits of hugelkultur as a method to break up compacted soil. Again, the issue was that mulch takes less effort.

What’s needed is a field trial to answer a few questions. Would surface mulch alone work just as well? What is the effect of mounding? Would at-grade hugelkultur work better in dry climates? Does hugelkultur save water? Since I’m lazy and especially don’t like big dig projects I’ve decided to forgo a hugelkultur bed. But I also don’t want to completely dismiss the idea.

What do you think?

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48 Comments

  1. What were the comments (if there were any?) re: hugulkultur serving as a repository for subterranean termites???

    When we had a s-termite invasion in our house in Glendale, one of the things that the company told us was we needed to take out the rotted tree stump adjacent to the house, as those are often hosts for the termites. Not sure it would be an issue if the underground wood was well away from the house, but maybe not a great idea if too close to one’s foundations????

    • Second this on the termites. Up here in Bay Area and having grown up in Silverlake, we all have to be so careful about wood touching dirt. When they swarm up out of the ground in November and March, they’ll fly from that buried wood right to your house foundation!

    • I believe that subterranean termites can forage up to 150 feet away from the nest, so your hugulkultur bed had better be at least this far away or your house timbers could be at risk from the evil, grazing beasties.

  2. I made a bastardized hugelkultur bed this spring that was part hugelkultur, part sheet mulch. It was a heap of branches,blackberry canes that I had cut into manageable lengths, compost, bedding from the chicken coop, and whatever materials I had ready for compost, some rotted leaves and branches pulled from a pond I was trying to restore, and some fill from a random dumped pile of fill I inherited…all topped with a thick layer of straw.

    I planted tomatoes and pumpkins. After they were established, I more or less completely forgot about them. They grew like gangbusters, never needed watering, and were the most low-maintenance garden plot on the property.

    My thought after this benign-neglect experiment is to make this bed a kind of continual mulch – continual hugelkultur bed. I’m sure what I’m about to say is sacrilege, but I’m not sure the specifics of how you make a giant mulch bed really matter!

  3. I just watched the doc Back to Eden, which is long, Christian, and mostly interesting. He advocates for heavy mulching with chipped branches.

    In short, if you have good soil, mulch heavily with chipped branches, and plant in the soil. If you have poor soil, build a lasagna garden, then mulch with chipped branches, and plant in the lasagna.

    Here are some good links. The first compares hugel to mulch, and has lots of sciencey links.

    I just watched the doc Back to Eden, which is long, Christian, and mostly interesting. He advocates for heavy mulching with chipped branches.

    In short, if you have good soil, mulch heavily with chipped branches, and plant in the soil. If you have poor soil, build a lasagna garden, then mulch with chipped branches, and plant in the lasagna.

    Several people also point out that the film’s claims about not needing fertilizer are overblown, as he applies manure.

    So, I am with you that nature mulches. I am going to apply heavy mulch of chipped branches after I re-contour our yard a bit.

    http://forums.permaculturenews.org/showthread.php?12368-Anyone-here-use-the-quot-Back-To-Eden-quot-gardening-method

    http://forums2.gardenweb.com/forums/load/cornucop/msg0416150730747.html

    http://forums2.gardenweb.com/forums/load/cornucop/msg0416150730747.html

  4. I don’t do hugelkultur. Not from any philosophical or scientific standpoint, merely from the idea that I don’t have a place to bury logs. I’ve read much of both sides’ arguments and I find them very interesting. I’ve thought that as I live in the desert in Las Vegas, I could really like the idea of the water conservation quality of the concept. But, I’m not ready to dig a pit and bury my neighbor’s trees.

    But because I live in the desert, I have to be sensitive to my water use in my garden beds. Mulching isn’t so much a fun thing to to, it’s a necessity. $10 of straw will last me the entire year, all three growing seasons. $10 of water won’t get me through the end of next week. So I mulch.

    A couple of years ago, I watched the film “Back to Eden” which explains Paul Gautschi’s concept of woodchip mulch. I was so impressed with that, which is kind of like hugelkultur on the surface, that I got a friend of mine who is a tree-trimmer to dump a load of his chips on my driveway. (Careful how you quote that line.)

    I’m really glad I did. My water use plummeted. Instead of twice daily waterings pre-mulch and thrice weekly waterings post-straw-mulch, in July I can get by on ONCE a week waterings with woodchip mulch. I don’t have to replace it when the wind blows; the stuff doesn’t move with the wind. I have NO nitrogen loss in the soil as it isn’t in the soil, it’s on top. And it does degrade into nice, black humus that my worms love.

    I don’t plant into it, I plant into the soil below it. I have to pull it back until the seedlings pop up and are tall enough but I don’t have that step when I use transplants.

    It’s free. It looks good. I can walk on it barefoot. No weed seeds are introduced. And, it has a generally cooling affect in the garden in the summertime. I’m trying to find a reason to dig pits or trenches and bury logs, but I just can’t. Especially when the woodchips are free, last at least three years (so far, still going strong), are easy to work and save me so much water.

    I think I’ll wait for the peer-reviewed hugelculture studies come in. Or at least until they come up with a name that’s easier to say.

    • Thank you for your input. I too saw the Back to Eden video and have considered the wood chip mulch. I live in the high desert in CA so also have the heat and wind problems. I am waiting for a tree trimmer to come through with the mulch and hopefully this will help to cut down on my water usage and help the soil. Good to know that another desert person has done this and is happy with the results.

  5. Since there appear to be other ‘desert’ gardeners out there I am wondering if anyone has done the sunken beds for veggies? I have heard that they are better for dry areas then the raised beds which tend to dry out more? I am already planning my spring vegetable garden and would appreciate any input. Sorry for getting off the subject…there is NO WAY I am digging holes to lay tree branches and debris. My soil is too hard and compacted!

    • 4500′ in Arizona here. my beds are sunken “pots”. to keep the gophers out the beds have to be lined. I’ve got one lined sides and bottom with pavers, one lined bottom with fine screen and sides with pavers. Still dry and need to be watered frequently (yes, I should mulch, but have the ground termite thing happening here) and shade cloths are a must have. Getting old enough like my raised beds, but the sunken beds do work better

    • I’m in a pretty dry area (700+ mm/year) on poor sandstone soils. I figured that a mound of soil over woody material would be almost constantly too dry for growning anything, so I dug trenches about 300mm (1 foot) deep and filled them with logs that had begun to rot, branches, and chip mulch, and then covered it with a raised garden bed.

      The results were pretty spectacular. Compared to adjacent raised beds the modified hugelkultur beds require less water, and have more vigorous growth. Over the course of 18 months the soil level dropped about 200mm (9 inches), which I have seen reported by others who have used the same approach. When I add more soil to top it up to the original level, the benefits continue.

      I’m not sure I’ll keep doing this for other beds though, because I can’t just dig out the soil to make the trenches. About 1/3 of the “soil” is broken sandstone rock and gravel, and this has to be sieved out. The amount of work involved seems a bit much for the returns from improved production, but I’m still thinking about it.

      The theory of hugelkultur isn’t too far away from what is often observed here in relation to heaps of logs pushed together after land clearing. These are usually burned once the clearing is done and before the new land use is started (I know, it is totally wasteful, and generates lots of greenhouse gases – but this is Australia, the not-nearly-as-green-as-it-pretends-to-be country). If a heap of logs isn’t burnt, after a few years it is obvious that the soil under the heap has become extremely fertile and holds moisture much better than surrounding soil. Our neighbours have one such heap, and they adopted the practice of planting into the heap (requires some interesting acrobatics to reach down to the soil in the middle of the heap). The result is a very productive area, with no inputs at all.

  6. From the illustration in this post, it appears that hugelkultur would only work if one has garden gnomes or hobbits about. Somehow doesn’t look right for LA 🙂

  7. I have 14 raised beds in my vegetable garden. Four years ago five were done hugelkultur-like with buried wood and branches. Those five continue to out produce the rest.

  8. Luddene Perry, it would be helpful to know where you are and what climate or soil conditions you’re working with. 🙂

    Like many of you, I live in a drought prone area with heavy clay soil (compacted because it’s suburban) that is a challenge to dig into. For the sake of The Science, it’s a shame you’re not experimenting, Eric …

    … but honestly, I wouldn’t wish that digging on anyone who isn’t living in a moist, deciduous forest biome where the leaf litter has already created friable humus.

    • I live in Nebraska – zone 5. This past year had sufficient rain and was slightly cooler, the three previous years were drought and very hot. I also have a large section of the yard done in a “forest garden” and heavily mulched mostly card board and grass clippings. The soil is mostly sitty loam. Yeah, I know, it doesn’t compare to hard packed clay.

  9. This year is the first year I’ve built hugelkultures , so I can’t speak from personal experience yet, but I’ve had several good friends praise them in our temperate michigan climate. I’ve set mne up along my steeply sloping side yard to (hopefully) functions somewhat as swales would, to slow down and hold runoff. We’ll see how it works.

    But to the statement that nature doesn’t hugelkulture, don’t fallen trees & root balls generally collect organic material, such as leaves, etc as the wind blows across them? To me hugelkultures are taking that sort of tendency and expanding on it. I know those upturned root balls of dead trees always seem to have a lot of rich growth on them, even when they’re well above grade. An upturned root ball seems a lot like a hugelkulture to me, at least.

  10. agree about the termite habitat. BUT also see that these would create berms, ready to catch water for you when it finally does come. as they say, you pays your money, you takes your chances

  11. For me hugelkultur is a great way to create mounds in the yard that keep the little bit of moisture we do get in the yard and keep it from running off into the street. Drought tollerant plants that are good at scavenging for moisture are getting planted on these mounds. Seems to be working so far and requires a lot less work than bringing in soil, etc to do it since I am using things I cut down.

  12. I’m over in the Owens Valley,with our precip the last several years being barely over 2″ ea. year.That includes h2o melted out of snowfall.I think the only way a hugelkultur would work in an area as dry as this would be to do it on grade.And would require alot of irrigation to get it going.We work a 1/2 acre market garden on pretty sandy soils.We mulch,mulch mulch.Straw,grass clippings,wood chippings.The grass clippings are best on small seedling beds,like carrots,beets.Once the plants grow up we get the grass on 4-6″ thick.If you pull that back in the middle of the season the worms are everywhere.The wood chippings are good too and last a long time.We use raised beds but do not really need to.The soil warms up plenty fast and certainly drains well.The interesting thing to see is how great the soil building is in the pathways.Stuff is always falling off the beds and landing in paths.If the paths happen to get some overflow water they gets some great humusy soil forming.So I am seeing the light of sunken beds.However since we are running a market garden and have alot of harvesting the sunken beds are much harder to harvest and one needs wider paths or they collapse into the sunken beds.I am learning the key is lots of organic matter no matter how you get it.A fair amount of supplemental water to jumpstart things .And the mulch.The biggest failing I notice with people attempting to garden in this area is not getting enough water to the crops.Remember it literally never comes from the sky.

  13. Hugelkultur does not appeal to me personally.
    Buried timber takes many years to compost down.
    During which time you can’t sink a spade into the soil.
    Maybe OK for planting perennial trees into.

  14. I think you mean mulch, not much here:
    “previous Root Simple blog post for the reasons why much does many of the same things”

  15. We began one experimental hugel mound for blueberry bushes that we plan to plant in Spring and we’ve had huge success. We used crepe myrtle branches from our trimmed tree and built a mound about three feet in April 2014 that settled to about 8 inches. I didn’t dig, I laid everything on top of the wet cardboard. This summer I planted tomatoes this fall to test the bed and I have monster tomato plants covered in fruit (that is until our hard freeze last night). I have only watered this bed about 5 times since April. Granted, we received great, normal rainfall this year, not the drought we’re used to. Due to the success of this bed we’re replacing all of our raised beds with hugelmounds. Our current raised beds are the 8″ concrete brick type and they are baking in our hot Texas sun. I have had very limited success with our current beds, even with ollas (I refuse to drip irrigate).

    • I forgot to add that I’m in Houston Zone 9b and one of the main reasons we decided to build hugels was because our backyard floods up to 1 foot in heavy rains, roughly 3-4 times a year (not counting freak hurricane rains) and it always floods during prime planting time. We are going to build the hugels as swoosh-shaped berms to catch all of the water on our (urban) property and keep it away from the foundation.

  16. The forums at Permies.com have location specific threads where folks discuss hugel for their climate. There are also a lot of before and after photos and videos including a huge hugel /berm in San Diego. They use excavators so no hand digging. I’ve helped on several sunken SoCal hugel projects. I didn’t think that termites would be a problem with the amount of water in a hugel bed but don’t know if that’s true at all. I mulch with composted bunny manure and straw and wood chips but the organic matter breaks down do quickly I don’t do a good job of keeping up with it. Where do you get your free wood chips in LA?

  17. I’m in Canada where it’s too cold for most termites but there’s no shortage of ants that dearly love things like hugelculture beds. As it is, I have to continually fight their colonies out of my raised veg beds and temporary soil piles; there’s no way I’d do full battle with hugel beds.

    I’m also at an age where, even if I could find them, hefting around logs and assorted hunks of wood is simply too difficult and tiring, aka a waste of energy. I’m sure for some this is a great solution, but for me I’ll stick to spreading free wood chips obtained from my town. The ants give them a very wide miss.

    • Great point. I’ve kept a keen eye out for termites and haven’t found any so far. But more importantly, my neighborhood is basically one giant fire ant mound and I’ve chased them out of every raised bed I’ve made so far. I’m hoping the moisture in the hugel mounds will deter a large colony, but it’s certainly an important thing to consider.

  18. I think there’s a little bit of missing the point going on here. Although permaculturists can jump on a bandwagon like everyone else, permaculture itself specifically teaches us to use the *appropriate* solution *for the situation we’re facing.* Hugelkultur is a brilliant solution to a specific set of circumstances: I have brush/branches/trees/woody matter in a temperate climate that I have to deal with. My options are 1) burn it, 2) take it to a communal facility to be chipped and composted (often at a cost), 3) leave it in a brush pile for the critters who like such things and watch it SLOOOOWLY decompose over several years, or 4) build a hugelkultur bed. Option 4 allows me to build soil, produce food, sequester carbon like crazy that would otherwise be released from burning, shape my landscape with water retaining berms and retain water like crazy in the growing bed I’ve built.

    Personally, I think hugelkultur is amazing under the right circumstances. But if those circumstances involve trucking material from other places just so you can have a garden…well, yeah, maybe it’s not the right option.

    And for the record, hugelkultur does not date back to 2007. Good grief. Even if you believe its an invention of Sepp Holzer’s, he’s been using it on his massive property for decades. And while I’m an academic who loves science, it’s no surprise that there’s not a lot of peer-reviewed research on something that’s so non-commercial and small scale (although there might be more German research?). People who love it love it because it works for them. I’d love to see you both run the experiment at the root simple homestead!

    • Good points! That’s exactly why I turned to building so many Hugel beds on my property– we cut down a lot of scrubby weed trees and I didn’t want to chip all of it. Hugels seemed an appropriate way to keep that organic matter on the property while also helping to slow down water flow on my steep slope, and give me extra growing space on my small urban lot by building up in three dimensions.

    • Good points! And while I’d love to run the experiment for the hell of it, Erik won’t help me dig (I suspect reluctance to dig is the true heart of his hugelkultur resistance), and I’m far, far too lazy to dig down 3 feet by myself.

  19. “have brush/branches/trees/woody matter in a temperate climate that I have to deal with”
    Excellent point.
    If you you have a lot of this material to deal with, it could be a good option to surround it with dirt and keep moist, so it breaks down and enriches the soil.

  20. I did a half-assed hugelkultur when I planted my fruit trees. I scattered branch trimmings around the tree and then covered with dirt. I like the idea of hugelkultur beds, but I don’t have a surplus of trees.
    Would a pile of wood chips then covered with dirt do the same thing?

    • Melissa, If you first spread a thin layer of composted manure down and then the wood chips on top, you won’t have a problem. I did this with my first year of chip mulching and had no problems. Most people seem to skip the ‘composted manure first’ part and think things will work out. I didn’t add another layer of soil on top since there was little need – the wood chips held in moisture and stopped most weeds. The resulting crops were great.

  21. I live in Detroit and we have been experimenting with hugelkultur beds and swales. We have a few in various stages of growth. One, now at the end of its second season, surrounds our intensive garden on 2 sides, the width of about 2 city lots. This year was covered in edible/medicinal herbs and flowers (lots of white sage bc of an awesome post of yours), numerous varieties of berries, a few fruit trees on the inside of the berm, volunteer pumpkins, and towering sunflowers. We live in a largely vacant area (house-wise) with access to brush, logs, and have tree trimmers regularly drop wood chips in the neighborhood. We dug a trench, filled with brush, rotting logs, old horse manure from a local stable, green waste, and bc we didn’t have water when we first moved in to our house for a good few months we peed in buckets and dumped on the berm for added nitrogen. We have another small hugelkultur that is in its first season, potatoes and sunflowers growing, and a third big one that surrounds about 6 city lots on 2 sides that is mostly brush with some soil right now. The large one was partially created to discourage vehicles from driving on and dumping trash, which used to be an issue. Now it surrounds a field of wildflowers, with the plan to become a mini food forest. The berm is wacky and meanders and has variation in height and width. I love the elevation and undulation the land has around us because of earth shaping, it adds visual interest in an otherwise flat piece of land. It gives us privacy when we work in the garden without being a fence, it creates microclimates in our yard where we can grow different things depending on location, it gives us more vertical space to plant, it sheilds the garden from high winds and road pollution, and bc of all the organic material it creates soil that is full of life. When that wood decomposes it holds water like a sponge, we only water the berms to start off seeds or transplants. Obviously Michigan is a very different climate than LA, especially this year with all the rain, but I would totally go for it if I were you. What harm could be done from adding a bunch of organic matter to your soil? It could be super successful. If I weren’t across the country I’d come help you dig.

  22. ive done it with great success, the mound was only about a foot tall after a week.

    On another note, is it true you guys trademarked the term “Homestead” and started suing others for using it?

  23. I feel like this would be a great thing to do in a rain heavy area such as Portland, Or. There is already an abundance of trees and logs, and all I can think of is what an amazing bed for mushrooms this could be! There is a new mushroom book out at chelsea green, the organic mushroom farming and remediation once, and I bet some of the mishroom innoculating and growing methods would work great with this.

  24. A friend just introduced me to your website. As a small farmer and beekeeper, I’m very much enjoying your blog.
    I made (and wrote about) a hugelkultur in my yard. I am not convinced that it works any better than raised beds or even my regularly mulched and compost-supplemented yard. I thought it might be a god thing to put under an oak, since I didn’t want to water there, and mounding the soil would protect the plants from the inhospitable soil under same oak. I planted herbs in it. The jury is still out. I’m constantly having to add more soil, because GRAVITY. The thing is always sliding down and decompsing. Also seeds haven’t done well in it, I think because it’s a living compost pile and it’s hot! Anyway, the jury is out here.

  25. I have build a hugelbeet because I wanted to but even before planting it had its advantages.
    The soil I want to build on it full of couch grass. It’s a pain. Ive heard the best way to be rid if it is to dig it out and then keep on top of the weeding. Where we’ve mulched we’ve still had a problem with couch grass. We have to dig out anyway so might as well throw some wood in the bottom before refilling.
    Whilst clearing and digging we discovered by accident one of the patches where a few years before a pile of horse manure was dumped. Beautiful soil. We’ve got it and are using it, without the hugelbeet it might not have been discovered (because big site and how we’re expanding the growing area and where we choose to site the beet).
    Mulch is still a wonderful thing but I wanted to experiment with hugelbeets the better to know them and the better to know how to use them.

    Unless anyone has a better suggestion for tackling couch grass?

  26. In your post you said that nature doesn’t hugelkulture, I disagree, I have seen numerous examples of fallen trees in wet temperate areas that look exacly like this, but without the top layer. Birch tree especially often sprout seeds as they decompose, as to the large douglas firs of the Pacific North west. Of course in nature this process doesn’t start for 5-8 for birch, or 20-30 years for a typical hardwood. The top layer simply jump starts this process. And again for a wet climate, the nutrient retaining capablities of the decomposing wood will hold the nutrients closer to the sufface as opposoed to leaching them out of the system. I’m not sure how this would pan out in drier climates, but walk into any old-growth forest and you will see numberous examples of fallen logs serving as soil/fungi matrix. As a side note, none of these climates have termites. The closest we have is a wood ant that leaves behind this wonderful sawdust the texture of wet spagnum moss.

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