Kitchen Garden Forum

Has anyone heard of this ? tried it ? Recommend it ?

It is a German idea, as you might have guessed, and seems to be a sort of raised bed. But it is formed of a mound over rotting wood. Googling it produces mostly permacuture avocates, but adding a touch of credance maybe is this article by Alys Fowler in the Guardian.

Why am I interested, when normally I don't favour raised beds ? At the bottom of my allotment, my last bed is underperforming. It gets very wet down there, and the soil isn' t great. The light could be better but for an overhanging silver birch. My thought is that this is an ideal spot for a raised bed of some sort; I have a fair amount of already partially rotted pear wood, the good stuff being destined for the stove, and a small collection of stumps etc. The overhanging birch tree might be persuaded to fall in too I can also skim off my paths, which were woodchip a couple of years ago but are now well composted and growing grass; the whole lot could go on in an inverted layer.

My main cause for doubt is that decaying wood might be expected to deplete nitrogen. Adding the grass sods should help, but also I could grow leguminous crops/green manure, and/or water it with high nitrogen liquid (No, not that one, I was thinking of nettle juice).

Anyone have any thoughts ?

I've not heard of this Tony but one problem I could possibly forsee in building any raised bed on a foundation of rotting wood is that you could possibly breed for yourself a plague of woodlice who seem to love any snug places like this. I'm not sure whether burying the wood deep enough would deter them. i have a strawberry bed border up against some low rotting fence panels and the the woodlice had a field day this year with my strawberry crop.

I suppose it could also deplete the nitrogen level but my main concern would be woodlice or possibky slugs who might regard the edges of the bed, where they can escape from any buried wood to the surface when needed as an ideal breeding ground. Also, Would the rotting wood tend to make a soil a little acid?

Ditto Primrose!

I was thinking about wood lice as well, but if a bit shaded they might not be as happy? Probably worth an experiment though Tony, if it is an underperforming part of the plot.

Westi

There could be one unforeseen advantage of adopting this method although it could take several years to see the end results and that is creating a breeding ground for stag beetles who are now becoming an endangered species. They breed in decaying logs and wood and the larvae can take up to eight years to gestate. The larvae feed on the decaying logs and they probably live underground during this time although it might depend on how deeply your decaying wood is buried.

They are magnificent creatures if you have the chance to see them flying around so maybe you could do your bit towards their conservation.
More info here: https://ptes.org/campaigns/stag-beetles/

On second thought though, if the area is very wet this might not be the right environment for them and you could find that rotting down the wood simply encourages a lot of mould and fungus which damages or kills the plants you're trying to grow. Would watercress or land cress work as a crop ?

Well I would love to think I've added to biodiversity along the way, nice thought Primrose. Though I hope I don't just get more slugs and woodlice ! the wood is well buried, so I hope not.

I have now a mound at the end of my plot looking like a giant shallow grave. Dug out 1 spit deep. Logs, followed by the chopped remains of my slug eaten brassica for a bit of nitrogen, then the soul back on. Topped off with compost.

It's now a steep sided mount with a flat top enough to receive a double row of broad bean Aquadulce Claudia in a couple of weeks time. I'm hoping that legumes will cope with the inevitable nitrogen depletion, and that the 18" or so height of the hill will keep them out of the worst of the wet heavy clay overwinter. We shall see.