In part 2 of the Geoff Lawton interview Paul and Geoff mentioned that hugelkulture was not really suited for warm climates because of the rapid breakdown of the wood. This was the first I heard of this. I'm in zone 7b, which is quite warm. Does this mean I shouldn't be putting in hugelkulture beds? My reasoning, besides the 45 to 60 days we go without rain in the middle of the summer was to improve the soil texture because I'm also super heavy clay.
I'm in a warm climate (Zone 8 ) and using buried wood beds which saved my vegetable garden this past summer. High temperatures of 95 - 100F for about a month, extreme drought (about 11 inches of rain so far this year). I had to irrigate but the buried wood areas needed less irrigation and in fact the unimproved parts of the garden died even with irrigation. Maybe this will be a short-term effect but I can't see any downside in adding such large amounts of carbon to the soil. Soil is clay.
Just my personal experience and I'm not an expert.
'Warm' is relative, but I think it's in tropical areas that decomposition is really too fast for hugelkultur to be an effective solution.
While Ludi's desert is really hot, it's also really dry, so wood won't decay very fast.
I say go for it and report back
Thanks for the comments. I'll be putting them in next week in preparation for next spring's planting unless someone comes along and tells me not to. I can't really see much downside, and since they will be at the back part of the property where irrigation isn't practical I figure its worth a shot.
I don't think that heat is the problem. I believe the problem arises with the combination of heat and humidity. A hugle bed will last many years longer in 100*F Arizona than it would in 100* Alabama due to the presence of high humidity.
Even after the wood has decomposed, there will be new fungal life in the soil, which will continue building richer soil.
I suggest hugelkulture is excellent in warm, humid climates.
It's all about the life in the soil and how it changes and promotes further life. Warm and moist will break down the wood much faster...I've seen swampgum and hickory, 3" thick, consumed in 3-4 years when used as the sides of my beds. That means all the stuff in the wood is converted to life sustaining material in just a few years. Being impatient, thats good news for me. I would not want to have to wait a decade.
Besides the breakdown of material into usable nutrients, the wood seems to serve as a trap in my sandy soil. Nutrients which would otherwise drain away with the rains is held in place by the wood and organic material it is broken down into.
Other than being labor intensive, I've found no disadvantages.
I can cover a bed with compost when I start a crop. By the time that crop is harvested, the compost is gone. The sand is back to where I started, with more compost needed for the next crop. With the wood in place, the plants still have access to at least some of the nutrients left behind from the last batch of compost.
Mind you, I still have a long ways to go in watching this stuff work. I built a hugelbed about a year and a half ago. It is time I dug it up to take a look at what is going on in there. I've walked on the bed, it is springy. Where the land is sand and grass, the sand settles in and is firm to the step. Where the sand is bare, it's like trying to grow stuff on a beach. The soil is desperate for help. I'll take every advantage I can get.
Seed the Mind, Harvest Ideas.
Being someone who lives in the tropics... I don't see any problem. You might want to be a bit more selective in which trees you bury, though. Generally speaking, for the tropics, you assume twice as much organic material needs to be added, due to how rapid things break down. You also have to factor in there is NO season where things "rest".
Think of yourself as having 3 times as long a season, and you are about right. This is because, even in a place like Florida, you do have a time when the trees lose their leaves, or at least, are chilled. Here in the tropics, we don't, unless it is due to a dry season, like in Guanacaste.
The big thing here is charcoal, it will last a long time, much longer than wood buried. But, I think I would use hugelkulture as well. We have so much wood waste in the form of sawdust and wood shavings, as well as lots of sheep manure, that we don't bother. We just pile it on, let it rest for a bit, and then plant. My system that seems to work pretty well is if I need a bed, break up the soil a bit with a garden fork (just a quick turning of the sod over), bury it in an inch of sheep droppings, or more, then put sawdust mulch on that. Then I plant on that. Sometimes I don't use the mulch, just broadcast lettuce, broccoli, radish, onion seeds and scratch the surface with a hoe, and then wait.
I might not even have to turn over the sod, I could probably bury it, but I like the exercise - and I collect a few worms to go fishing. lol
Sustainable Plantations and Agroforestry in Costa Rica
I listened carefully to Geoff's comments. I'm in Western Washington and right now it is wet! I'm making beds with hugelkultur because in the summer it dries up and I'd like to minimize my water use and increase my soil's holding capacity. In addition to that, I'm making biochar right along and adding it to the soil in the new beds. Because unless we are constrained by our particular situations, why limit ourselves? Why not do it all, according to our particular requirements and to varying degrees? It's all sequestering carbon and returning it to the soil.
I'm using the resources I have on hand, on my own five acres or close by. There is all the rotting wood around here that anyone could need for hugelkultur. Every day I get a bucket of coffee grounds from the local espresso bar. I mix it with the pulverized biochar to charge the char, and add it to the soil in the new beds, with sifted compost and topsoil. The used filter papers go in the compost. This all goes on top of the hugelkultur.
Ludi, clarifying my comment: I'm assuming a dry desert environment would be unfriendly to the wee beasties that break down organic matter, so while buried wood would have great water-holding properties, it would break down very slowly. Does that theory work?
Personally I think this is more about tropics/sub tropics vs. "warm". More like warm and wet and warm year round. I hate to say this because Geoff Lawton is one of my ALL TIME HEROES but the feeling I got was Lawton just really doesn't "get" hugelkulture over all. What he described with a banana circle pit was well, pretty much hugelkulture. Further he kept talking about "wood chips", I kept thinking "no Geoff, we use flippin trees".
I think Paul may have felt similar but let it go.
I figure it this way, 99% of Lawton's work is in the Tropics and Sub Tropics, you don't really need to do much more then mulch and swale in those areas so he just isn't familure iwth it. As far as hot I believe Holtzer did hugel in Spain's deserts with great results. Paul?
There are more unknowns than knowns at this point. What works in one location may not work in another. New ideas crop up all the time. I try things out just to see if it will satiate my endless curiosity. Sometimes I come up with a combination of techniques that really kicks butt.
Seed the Mind, Harvest Ideas.
I don't know if I'm answering some questions with this post or creating more issues to discuss, but I live in Guanacaste (dry area of Costa Rica) and this year I made my first Hügelkultur beds everywhere. I am still watering them while the seeds grow roots that go deep enough, and then I was just planning on spraying foliars, both to keep the plants disease-free, as I found all kinds of tiny bugs under the leaves of every plant sucking their lymph, and to provide Nitrogen, because, despite the chickpeas, maní, green beans and fenugreek that I have growing all over them, I don't see anything that looks deep, dark green (sometimes I spray water and urine, sometimes panchagavya, which is fermented cow dung/urine/milk/yogurt/yeast/sugar water, and today I added some epsom salts for magnesium).
By the way, my beds have a core of already rotten wood and decaying banana trunk, because we may make a parking area where that garden is now, so I need it to produce right away. So far it's going pretty well. Around the banana trunk core there is a layer of all green weeds, then a layer of dry corn husks and a layer of aged manure. I covered everything in charred rice hulls (mixed with the ones that didn't char, because my retort stinks), I sowed and i covered loosely with dry grass to shade the seeds. I find the charcoal to not be as water-retentive, maybe the one that's mixed with soil, but the top inch, where the seeds are, would get dry right away, so I had to water every night.
I'll post pictures soon.
Writing from Madhuvan, a yoga retreat/organic farm on the West Coast of Costa Rica.