What to expect when you're expecting (to bury wood in your garden beds).

OK now that I have seen the first signs of winter approaching (well pipe froze and broke this morning...) my focus will begin to shift from home and auto repair to land improvement. Going to create some hugel-beds!

Something I've always wondered about hugelkulture: They say that the wood inside lasts about 5 years before it breaks down. After that the bed will still be excellent right? No need to add wood again, ever? Will my nasty tan clay be sweet dark earth by then? Just wondering what to expect after all the wood is gone.

Irrelevant Backstory:

My first year garden beds started off great but in the dry heat of a Mediterranean summer they ended up "eating" all my organic matter and reverting to heavy clay and became hard as a rock and dry as a bone 6 inches below the surface. Water would just turn the top few inches under the mulch to slop without penetrating further. So the beds are gonna get huglified. I know this will help but I ran outta time last year. I plan on digging down about a foot below grade and filling with wood (and all the other stuff) to about a foot above. Then topping with about 4-6 inches of soil.

Hi Dan,

I am not into hugelkulture per se.  I do have some pretty deep raised beds that I have borrowed hugelkuture principles to build.  Yes, I have gotten black soil where there used to be clay.  Yes, I am happy with the results.  But, I have never declared victory.  I find I am always trying to improve the quality of my soil.

They say that the wood inside lasts about 5 years before it breaks down.
How long it takes to break down depends on your climate. For me, it was about 3 years, though my logs were more like 6" diameter, not huge trunks.

After that the bed will still be excellent right?

Yes, after it breaks down, the benefits will still be present for some time. The exact scientific formula to calculate how long the benefit lasts looks like this:  ¯\_(ツ)_/¯

No need to add wood again, ever?

Burying logs/wood is very beneficial. Nevertheless, it's just one thing among many you can do to help the soil. You'll still want to, for example, mulch the top with woodchips or grass or straw (or cardboard) each year.

Growing something in dirt, even weeds, depletes the nutrients in the soil. Over time, you'll need to somehow replenish those nutrients. Large commercial farmers for example inject fertilizers into the ground when planting seeds. More eco-friendly gardeners find better ways of replenishing the soil. This could be through adding chicken manure, cow manure, horse manure, etc... to the soil, as well as mulching.

For myself, I don't do a very good job of being consistent, but some garden beds I bury fish, chicken intestines, turkey carcasses, and etc... in the beds. I don't have any vegetable scraps (my chickens get them), but other gardeners bury their compostable waste into the beds (for example, google "keyhole garden beds" for the general concept, where a compost bin is integrated into the garden bed) - this can be as easy as just using your hand to make a trench, adding your kitchen waste into the trench, and covering it back up. Other gardeners have a compost pile, and each year add some of their compost to the garden bed.

Since weeds also deplete soil, keep down weeds (by mulching, or cardboard, or whatever), helps keep the soil better for longer.
Exposed dirt also gets baked by the sun, and seems to suffer, so mulching does a double-whamy benefit (triple-whamy, when you consider how it absorbs and releases moisture, reducing water needs).

Will my nasty tan clay be sweet dark earth by then?

Your clayish soil will be improved dramatically, but likely won't look like (or at least won't remain like) what you're describing. It'll bring it alot closer, though.

Your soil doesn't need to be perfect, but anything you can do (even inconsistently / infrequently) is fantastic! And burying logs like that works great!

Anything else you can toss in the beds while burying the logs would also help. Kitchen scraps, manure, lawn clippings, leaves, fish, dead animals, any garden waste from this past growing season (e.g. dead tomato plants), leaves, etc... all is great stuff.

Just wondering what to expect after all the wood is gone.

You can expect the soil to be greatly improved, but almost nothing in gardening is "do once and now your garden is magic forever", alas! =(...

Burying logs is fantastic. Definitely one of the better things to do.

What you can expect is definite improvement in the quality of the soil. Another thing you can expect, is the dirt level in the raised beds will sink down, fairly dramatically. The first year you'll probably drop 20%, mostly just from the loose dirt compacting from rain, but over the next few years as the logs decay, it'll gradually drop another 10-20% or so. This is actually great, though, as it provides room in your bed for you in a future winter to revitalize the beds by e.g. put another layer of small branches covered by more dirt, next winter, as well as space for plenty of mulch when you're able to. My hugel bed I think dropped nearly 50%. At least 40%. The bulk of it in the first year.

I don't want to discourage you from doing it - it's fantastic, and you definitely should do it.
But I also don't want you to think it'll last forever (but it will benefit for multiple years!).
Nor do I want you to think that it'll take your soil to perfection on it's own (but it will be a major improvement).

It's one of the better tools available, and one of the longer-lasting ones.

One thing you can do on your older beds is even just rest a log on top of your old beds, just half-buried, half-exposed. Not as a great as a full hugel bed, but for supplementing existing beds, I've been surprised by how well that worked.

Jamin pretty much nailed everything regarding hugel basics - kudos :)

Although my experience with half-buried logs is not quite the same. As I live in a temperate desert, maybe with similar spring/summer conditions to OP, the log is always in a state of wicking up moisture from the soil which is then taken from the log by all the hot ,dry winds. This not only dries up the surrounding soil but keeps the logs from decaying - not so good for putting nutrients into the soil. There is a mini hugel in my yard from 3 years ago, 1 foot deep by 2 feet wide, where I didn't have enough soil to cover the top of it, and pretty much all the logs that aren't below ground-level are still hard to this day, which I am sure is due to the wicking effect. This is dependent on what your climate is like though, but I figured I'd mention it as OP talked about a dry summer.

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In comparison to the mini hugel which was barely so-so in results, I once had access to a larger garden where I dug a 4 foot wide by 3 foot deep (though it was also 3 foot above the soil in the end) hugel with a skid steer 3 years ago and it performed 2 or 3 times better..

I finished it in the middle of the first snow(storm) of that year, barely getting 1000L of water in it, and 1 foot of soil over it before it was too late. But 6 months later during the following summer all the logs in the hugel, even the top ones, had become soft enough to break apart by hand. It also shrank in size, as things settled and started to decay, so it was only about 2 foot above the ground by then.

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I'm not sure what you plan to plant into the hugel, but the reason I did mine in late fall is because most plants aren't happy in shifting soil(as the logs decay, earth settles, etc). The 6 months of waiting until Spring allowed most of the settling to occur. If you plan to make the hugel and then plant straight into them without a waiting period, the best bet are usually potatoes.

Dan Fish wrote:My first year garden beds started off great but in the dry heat of a Mediterranean summer they ended up "eating" all my organic matter and reverting to heavy clay and became hard as a rock and dry as a bone 6 inches below the surface. Water would just turn the top few inches under the mulch to slop without penetrating further. So the beds are gonna get huglified. I know this will help but I ran outta time last year. I plan on digging down about a foot below grade and filling with wood (and all the other stuff) to about a foot above. Then topping with about 4-6 inches of soil.

It takes awhile to reverse a clay-pan type soil. In the larger garden area, I used to try to plant potatoes into a heavy clay soil, and even after adding straw on top the results were poor for the reasons you outlined. So I borrowed a rototiller, put about 3 truck loads of leaves (say 6 inches thick) over the area, went over it a few times and then applied a deep watering and straw mulch. The following year the top 12 inches of soil had improved quite a bit to where digging wasn't difficult anymore, the straw mulch did it's job, and the potatoes were plentiful. That was the only time I had to rototill, and it only required straw mulch applications afterwards.

Poor luck on the pipes freezing, but best of luck with the hugel :)

Jarret Hynd wrote:my experience with half-buried logs is not quite the same. As I live in a temperate desert, maybe with similar spring/summer conditions to OP, the log is always in a state of wicking up moisture from the soil which is then taken from the log by all the hot ,dry winds. This not only dries up the surrounding soil but keeps the logs from decaying

Yeah, it's very climate-dependent, so YMMV. I get alot of spring and fall rain and hot dry summers.

Some people use cardboard as mulch and then complain it never rots and blocks oxygen to the roots of trees a decade later. Other people, like me, put cardboard down and it's fully decayed in a year. Ditto for woodchips - woodchips barely last me two years.

You know the worst part about online forums? People ask questions and don't even bother to say thanks...

I forgot I posted this. But hey thanks! Thanks for sharing your experiences and advice and thanks for the well pipe sympathy, haha.

I hope to bury logs this coming weekend, weather dependent.

I have a question about  burying  "fish, chicken intestines, turkey carcasses, and etc... in the beds."
Can't this create a problem with attracting critters who want to dig them up to eat them?