Do you think it will work

[rary]

This year my harvest was not as expected, and the soil was very dry, I even had to water quite regularly which is not normal, so once the beds were empty I dug down to check the soil and about 4 inches down there were lots of tree roots, as I work with 2ft. high raised beds this meant the beds were pritty full of roots, so I have now decided to build a larger raised bed sitting on a concrete bed the ends and one side are made with concrete slabs which are also sealed to the base with concrete, which hopefully will stop roots getting in the remaining side is built with timber, which should let any excess water drain out, as I also had to cut down an ash tree suffering with Ash dieback, I have used the wood to part fill the bed which hopefully will act as a water store in the future, a sort of hugelkulture bed which I hope will be a bit more environmentally friendly compared to burning the wood as there will be no pollution and as said less watering, so do you think I have given myself a lot of work for nothing?

[nick the grief]

I must admit I've not really looked at Hugelkulture but the problems I can forsee are

• THe dept may be an issue with some crops (carrots and parsnips for a start)
• the slabs may give you the opposite problem with it waterlogging due to poor drainage - depends how well they are sealed
• the large volumes of wood may cause a nitrogen depletion as it will suck the nitrogen out the soil to help break it down - I'd think I would ahve tried to chip it and compost it down seperately bixing it with something like Ammonium Nitrate which is roughly 21-0-0 and will help break it down, but if you do do this whatever you do , don't put your hand in it - you will burn your hand as it get really hot.

apart from that you should be fine

Maybe you could convert your old bed to a dig bed and the action of digging will help prune the roots in it.

[rary]

Thanks nick, once I get it covered with soil I will spread some chicken pellets over the soil then cover with several, layers of cardboard, and this will get covered with another layer of soil, then topped of with garden compost and seaweed, there will be no old bed as the soil from the old beds are being used to make up the new bed and also help make my flower beds a bit wider as for digging, my OH and my knees won't allow this

[ameno]

I have a small raised bed on my patio, 180cm x 45 cm x 45cm, and it sits on top of an old concrete path (I raised some patio slabs to install the bed, but it turns out there was an old concrete path beneath, and it was too solid to remove, so I had to build the bed on top of it). It has a sort of drainage runnel along one side, about 5cm wide, which does go down into the soil, but otherwise the whole thing it on concrete, and I have no problems with water-logging, nor with it drying out unduly in the summer.
Since yours is even bigger, I think it should work just fine. Although I would make sure there is at least some facility for drainage, either holes drilled into the concrete periodically, or else you could lay all of the concrete on a slight slope, rather than perfectly flat, and have a drainage channel at the downhill end.

[rary]

The concrete slab that the raised bed is on is level, I had actually made it as a base for my greenhouse though it is sealed on three sides I am hoping that any excess water will drain from the wooden side, which has a poly sheet tucked under the bottom board and protect the rest from being in contact with the soil, I think the water should drain out below the polythene, the large logs should eventually act as a sponge which will give out water as required

[Snoop Puss]

The only problem with hugelkulture beds that I've heard about are in the first year: dry beds and low nitrogen, as Nick points out. So I guess don't expect too much in the first year or get disheartened if the results aren't what you hope for. The second year could be much better.

[rary]

The only problem with hugelkulture beds that I've heard about are in the first year: dry beds and low nitrogen, as Nick points out. So I guess don't expect too much in the first year or get disheartened if the results aren't what you hope for. The second year could be much better.

I doubt it will be any worse than this year Snoop, I had to water regularly which is something I don't normally have to do, as I have been emptying one of the beds when I got 5 or 6 inches down the soil was as dry as dust and full of roots, as for the nitrogen depletion (I read that word on the back of a cornflakes box and wanted to use it) I am hoping that topping off with compost and seaweed will overcome this, how ever time will tell

[ameno]

as for the nitrogen depletion (I read that word on the back of a cornflakes box and wanted to use it) I am hoping that topping off with compost and seaweed will overcome this, how ever time will tell

It won't. Both are quite low in nitrogen, seaweed especially.
If you want to counteract it you need a fertiliser higher in nitrogen, like animal manures or a general fertiliser. Poultry manure would be good.

[rary]

Ameno, I am also hoping that the application of chicken manure over the first layer of soil will help reduce nitrogen loss due to the fresh wood, but as said time will tell

[Jungle Jane]

Include alot of green waste on top of the logs under the soil to help counteract the carbon,like in a compost heap,I don’t think chicken pellets would have the same impact as having the organic matter.

[rary]

Thanks J. J. I have a lot of dahlias and the likes to remove from the garden yet, so I will throw them in on top of the trees, I had intended shredding them and spreading it over the flower beds, but putting it on top of the logs will save me time.

[ameno]

Include alot of green waste on top of the logs under the soil to help counteract the carbon,like in a compost heap,I don’t think chicken pellets would have the same impact as having the organic matter.

It depends what the organic matter is made up from, but I would usually expect the chicken manure to have a greater effect.
The problem is a fairly simple one. The logs have almost no nitrogen in them, yet the fungi and bacteria which rot them need nitrogen to grow. As such, they take it from surrounding matter instead. To prevent it being taken from the soil in significant quantities, another nitrogen source must be added. Chicken manure is far, far higher in nitrogen than the average collection of compostable plant matter is. Most things one puts in the compost are actually pretty low in nitrogen, and the resulting compost usually is, too.

[Jungle Jane]

Sounds like the organic matter is dahlias etc all the old plants nutrients will give the nutrients to the wood as it all decays. I’ve only ever heard of mounding up green matter on top of the wood,not chicken pellets,in a hugelkultur bed. The green waste will help keep a good carbon to nitrogen ratio & it would be absorbed by the wood & released when rotting down,chicken pellets would be a good fertiliser for when you plant the veggies though or plant peas in there they can make their own nitrogen. You wouldn’t have a compost heap of brown’s,chicken pellets,browns,chicken pellets,can you imagine the compost from that. The green waste helps with the decomposition.

[rary]

Sounds like the organic matter is dahlias etc all the old plants nutrients will give the nutrients to the wood as it all decays. I’ve only ever heard of mounding up green matter on top of the wood,not chicken pellets,in a hugelkultur bed. The green waste will help keep a good carbon to nitrogen ratio & it would be absorbed by the wood & released when rotting down,chicken pellets would be a good fertiliser for when you plant the veggies

J J as I said in the first post, this is a sort hugelkultur bed, I know that generally hugelkultur beds are mounds built up from ground level, whereas I am basically burying the wood, after getting the tree cut down, I thought this would be an ideal way of using the wood rather than A/burning it, or B/leaving it to rot, as with hugelkultur I expect I will have to water the bed this year but see no reason why it shouldn't work in a similar way to the mounded garden, also if I don't try I will never know . Asking others for their opinion has highlighted points that I hadn't considered, so next year I will update how well or poorly the plot performs. Also until I get the bed filled I am still open to suggestions and thoughts

[Jungle Jane]

The green waste would help with the moisture content too,the texture & fertility. Good luck with it rary,it should save on watering. Have you got space for a log pile too,for beetles etc I throw all the Christmas tree trunks at the back of the shed & they always rot down over the years,it’s about one foot high pile or 30cm,nice to have wild areas for the toad & hedgehog to wander about in too