organic raised bed preparation advice sought
neilbradburn
Posts: 142
Hi all,
I'd very much appreciate peoples words on wisdom on my situation...
I am trying to create an organic veg garden consisting of 3 raised beds. I bought some untreated scaffolding boards and created frames for the beds. In somewhat of a rush (not necessarily self-propelled, I might ad!) we went out and bought several bags of multi-purpose compost to fill the new frames. Knowing that this lacked the necessary long-term nutrition, we also added slow release organic chicken manure pellets to the beds. However, having now digested a few books on the subject of organic gardening, it appears that I've very much followed the feed-the-plant, approach here, which is against the sutainable philosophy of organic gardening and am looking to correct this.
The compost I used was Clover Multi-purpose, which I understand to be largely peat based. Not brilliant for the environment I'm sad to say, but there's not a lot I can do about that know. However, on the plus side I believe that it means that the general conditioning of my top-soil is now reasonable, and my major problem is now lack of life in the soil; and potentially alack of organic matter for such life to break down - I think!? :-) Is my understanding of the situation correct? and if so, what do people suggest as a means to rectify it?
I'm looking to grow salad, root veg and brassicas on the plot, so I believe I do need some good nutrition in the ground.
IF it matters, note that the subsoil is clay.
I have to say that the more I learn about the workings of 'soil' when it comes to gardens, the less I know :-)
Many thanks in advance!
Posts
A humus rich multipurpose compost has plenty of organic matter to break down. What you are lacking is something like a good loam to mix with it. What you need are a soil based compost or top soil by the cubic metre.Some garden centres have a compost labelled for veg growing which is loam based.
If its any help this is what I did when I took over gardening next door. We made a raised bed area where the pigeon shed was. They has scraped down to subsoil which was clay and shale.
I put a six inches of well rotted farm yard manure on it ( I get a local farmer to tip me a load every now and then. It is a mix of cow manure bedded on straw and horse manure bedded on wood shavings.)
I topped that with a thick layer of rock dust (verve available from b &Q) a dose of 4 oz per square yard of blood fish and bone. I had some loam from a turf stack where I had skimmed a lawn off, and we topped it with that, then mixed it all in.
Its easier to buy good loam ready made and add some blood fish and bone.Just mix it all up well. The worms appear by magic.
Hi Fidgetbones!
Many thanks for taking the time to give such a detailed response! So you are saying that the peat does contain the necessary organic matter in order to go with an organic approach, but that I need soil micro-organisms to make this usable to the veg? And in turn, that the latter will be provided in a topsoil or loam based compost?
I will get my head around this... :-)
Many thanks!
Neil
There was a raised bed trial mentioned on the radio, and each bed differed in the amount it was dug. One end of the spectrum: no dig, the other end turned. They have been monitoring and growing in the beds for years, and the no dig bed is the most prolific.
I have done much digging in our garden really to see where the chalk starts, and to pull out rubbish that has been dumped there over the years. I just pulled out a mattress, and loads of other detritus. All for the benefit of a hedge.
I realise in doing so, I've stripped out most of the top soil, and plant matter. So I've added loads of horse manure and a bit of left over sharp sand. On chalk the living matter quickly disappears. And I wish I'd planted some green manures in sections of the garden that I've already worked. Something like comfrey, there are other options.
Not that I know much about soil, but I do find it fascinating. Especially as mentioned above how the worms just arrive.
Not sure if this was the trial, but might be of interest: http://www.charlesdowding.co.uk/no-dig-growing/lower-farm/
And: http://www.telegraph.co.uk/gardening/howtogrow/fruitandvegetables/10568420/No-dig-gardening-a-better-way-to-grow-vegetables.html
Hi Wayside,
Many thanks for taking the time to respond, and for the very useful links! I'll have a look at them shortly. Your comments re the effectiveness of no-dig beds seem to echo what I have read up to now. However, as you allude to, I think that a no-dig bed can require some up-front digging to 'prepare' it for the no-dig years ahead; so I guess the ideal approach is a combination of the 2.
I'm considering some green manure also. I've got some red clover seeds, and the beds will lay dormant for the next couple of months whilist I'm away. Not sure if that is a long enough period for the clover to grow to a size that would prove beneficial, but I guess I've got nothing to lose :-) I just need to make sure that they don't set seed before I chop and dig them, otherwise I could be in trouble..
Kind regards
Neil
I've not got enough space for it to be worth me doing it myself but if you are creating the soil from scratch, I was quite interested in the idea of Mel's mix, which is designed for veg growing in raised beds (although his emphasis is on getting the highest yields per square foot) and I think the idea is to get the soil ideal (and totally controlled) at the outset.
Here's a link in case useful!
http://www.mysquarefootgarden.net/mels-mix/
The links I posted referencing Charles Dowding, state that he avoids green manures because they attract slugs. And no dig means no dig. He dumps compost/manure on top and lets the soil organisms do the hard work.
I had the book Humanure, and in that it suggests that you place your rotted human waste in a bed, and grow a green manure that you then further compost. To avoid any nasties. Perhaps that would be better at keeping the slugs in check.
@endpaper, where would I get peat moss?
Unrelated, but what's the deal with mushroom compost - good or bad, cheap or expensive? As I have chalky soil, should I avoid?
Last edited: 17 June 2016 17:33:47
@wayside, I've just read the links you posted. Many thanks again! A very interesting study indeed! As usual, it seems like we need to let nature find its own way ;-) I'm now very much sold on the idea of no-dig; although since I've already dug this year, I'll have to start the process next year...
Also, interesting stuff about the effect of green manures on slugs. I wonder what others experience have been, as in my mind not green manuring is a real loss in many other ways...
I just need to make the final decision on what, if anything, I need to do with my bed mix of MP compost and chicken manure. @fidgetbones suggest some loam was needed, but before I commit I'd really like to understand what properties it adds to the current mix (too inquisitive, I know! :-) ).
Kind regards
Neil
The loam brings all of the essential micronutrients and the particles (essentially worn down rock) it contains provide surfaces on which all of the 'magic' chemical soil reactions occur. Your clay subsoil has all of those in abundance so you could just do an initial dig to mix plenty of that into it. Alternatively just buy some bagged topsoil and mix it in. A clay based soil improved with lots of organic matter is probably the most productive soil there is. Once you have it all well mixed you can use the no-dig approach and just put on a layer of well rotted manure each autumn and leave it to nature.