Does a hugelkultur bed sink as the wood decomposes?

I'm wondering about this in terms of permanent plantings.

And...as I'm writing this I am getting a very interesting and quite disturbing vision of sinkholes which, if you imagine the sinkhole as a cylinder that continues above ground to tree level...is basically the area of a tree canopy which would, of course, be matched underground by a massive root system which brings to mind a whole other method by which mother earth may temper our consumptive and destructive habits...crikeys...wish I hadn't thought of that...would someone please explain to me how that would be impossible, please? Thanks!

Editing to add a couple more pleases...so PLEASE, PLEASE and, just for good measure, PRETTY PLEASE??

Yes, they settle over time. Roughly built ones like those that I built with an excavator, will sink faster than those built carefully from larger wood.

Dale Hodgins wrote:Yes, they settle over time. Roughly built ones like those that I built with an excavator, will sink faster than those built carefully from larger wood.

Makes sense. Here's what I was thinking - to plant on top of post holes into which one has dropped a log(s). So one would want a mound or small raised bed on top of that. For a permanent planting like a bush or row of bushes.

I have an area surrounded on three sides with a 6 - 8 ft railroad tie retaining wall in full sun that gets plenty of rain but dries super fast. I basically have two crops of weeds - one wet and one dry - that take turns on that patch. We're into a very wet spring after a considerable drought so the little wild strawberry things seem to be doing OK, but with the scary thought...I'm not sure about the logs, now, as it is right at the end of a long concrete drive and only a couple of yards from the corner of the house so it wouldn't take much shifting to do some serious damage...I dont' know. Maybe I'll just brick over it and add some kind of shade structure...

The retaining walls are going to have to be replaced as the ties are decomposing - so I'm working on an idea for a retaining wall that will keep it from drying out so fast...well...actually, I just REALLY want to play with one of those "bullet mole" things, ROFL! Now that I think about it, piercing it with the pipe and the flanges on the ends should add some stability with regard to decomposing logs....I'd still have to retain the end wall, but that shouldn't be a problem...

so, Cindy, you know that railroad ties are full of toxic stuff you don't want in your vegetables?

About your house foundation, keeping it wet enough for vegetables or plants can be a problem, not to mention sinking wood near it that could attract termites. I've switched to big pots on big saucers near the foundation.

It sounds like you want to make a vertical posthole and fill it with a log? That will sink and settle much more than a horizontal log that stays consistently wet a foot or more below the surface. A long, skinny hole in the ground that has 50% of the wood near the surface will not be as wet for its full length, nor be as amenable to soil critters who want to live in and around it.

Driveways are expensive to maintain if they start cracking, and drilling under or around them just might cause something like that

Cristo Balete wrote:so, Cindy, you know that railroad ties are full of toxic stuff you don't want in your vegetables?

About your house foundation, keeping it wet enough for vegetables or plants can be a problem, not to mention sinking wood near it that could attract termites. I've switched to big pots on big saucers near the foundation.

It sounds like you want to make a vertical post hole and fill it with a log? That will sink and settle much more than a horizontal log that stays consistently wet a foot or more below the surface. A long, skinny hole in the ground that has 50% of the wood near the surface will not be as wet for its full length, nor be as amenable to soil critters who want to live in and around it.

Driveways are expensive to maintain if they start cracking, and drilling under or around them just might cause something like that

I gotcha. Thanks. I wasn't going to use it for veggies because I have no way of knowing what it's filled with and because of the railroad ties - which are obviously not good. I just want something to grow there besides weeds. I figure any "good" growth would help clean it up. I was looking at it just now and it's quite swollen upward so bricks or pavers aren't going to work. Poop.

It actually has a tree growing quite aggressively out from between two ties, about 2 ft down from the top, behind a little shed that is currently up against the end. I've cut it off several times but it comes right back. Of course, merely cutting it is probably like pruning which trees love so...I don't know.

Termites are plentiful around these parts but I've never had a problem. I don't know why, unless it's because I'm right at the top of a drop in elevation with plenty of houses sitting on much wetter ground. This little piece of ground has its own unique climate compared to the surrounding properties and it's changing even more, now, because I lost a shade tree so the whole south side of the property, right next to the drop in elevation, gets full sun all day.

Oh well, it's interesting. Guess I'll play with it and see what I can do.

Thanks for your reponses (both of you).

Cindy Clark wrote: Thanks. I wasn't going to use it for veggies because I have no way of knowing what it's filled with and because of the railroad ties - which are obviously not good. I just want something to grow there besides weeds. I figure any "good" growth would help clean it up. I was looking at it just now and it's quite swollen upward so bricks or pavers aren't going to work.

Let me speak up as one of those that is not scared off by railroad ties. Especially ones that have extensive rot and Phanerochaete chrysosporium growing on them when you turn them over. If half of the railroad tie is eaten away by fungal rot, like many of mine are, then what was used to creosote it a century ago is no longer there to cause problems for other growing things.

Cindy, I thought maybe you were going to replace it with more railroad ties. I have a lot of faith in compost, and if you got the old ties out of there, maybe take away the soil that was directly touching them, then build really thick layers of manure, straw, mowed weeds that will start breaking down, the soil in that area will improve. You might not want to plant food in it the first year, but you can have it tested for residual creosote or whatever was in there and see if a year's worth of serious composting for 12 months straight has helped.

Since you say it's "swollen", not sure what you mean by that, but there are other safe edging materials like cinder blocks. You'd need to dig down, make a trench to bury the first layer of cinder blocks in the trench as a footing, then build up from that, overlapping the cinder blocks. Where two come together, put one on top overlapping where they touch, don't stack them up directly lined up. You can plant herbs and flowers in the cinder blocks, too. It may only take 2 layers blocks depending on how you want it to look. They can be painted or there is cement stain in natural colors that looks good.

You are lucky about the termites. So that probably means there isn't any dead wood near your house or under your soil. Hugelkultur uses dead wood, that's what termites eat, and they will find it!! Although if the wood is wet enough, really wet, they might not like it. Still, you wouldn't want a lot of water around your foundation.

Soil test show that those creosote railroad ties can be broken down by fungi, for sure. I would have a tendency to parent crop with with the red garden giant mushroom and plant some non edible companion plants like lupine, straw flowers and maybe some flower bulbs ( good as a secondary income or area beautification) as well as a good nitrogen fixing cover crop for when you detoxify the hugel beds. At our place we use vetch and clover as well as a mix of alfalfa and barley to mix up the root depths. Don't forget to get a decent inoculant for your seed when you plant it so you can enjoy all the nutrient fixing benefits. Our hugel mounds are in their third year and a rocking out number crops of potatoes, garlic, corn/beans/squash, tomatoes, all kinds of medicinal herbs and spices as well as some fruit trees planted down hill to block the wind an retain the back fill. Happy hugelkulture and have fun.

Good to hear, Shane