Monday, 4 January 2016

Another reason for not having raised beds?

Way back in the 1970s, when I was teaching, there was a movement to use school grounds as a learning environment rather than just a green desert of Italian rye grass. 

One of the school grounds ideas was to develop a scented garden with herbs and other interesting smelly plants.  Another idea was to make a disabled garden where children with disabilities could garden with impunity.

I had plans for a scented garden to have a sunken path through it so that the children could be at nose level with the plants.  The disabled garden would have raised beds, have scented and tactile plants which were accessible to children who had limited mobility and sight.   Many schools took on these kinds of projects and lots of them have raised beds from the 1980s just for those reasons.

There were no boxed raised bed systems on allotments that I remember.  Some allotments had wooden edging but mainly it was edging plants like box, lavender and rosemary; if anything at all. 

During the Victorian era and earlier the British walled kitchen gardens were dug with beds where soil from paths or alleyways were thrown up and levelled out.  In addition, large areas of the garden were used to make hot beds which were raised mounds of fresh horse manure.  Both the raised beds with alleys and raised hot beds did not have boards to keep the soil in place. 

The best modern example of this is the methods recorded on
The American tradition of raised beds seems to have originated from Alan Chadwick’s writings.  The beds were about four feet across and allowed access from both sides.  About the same time as Alan Chadwick was lecturing in the United States Bill Mollison was developing similar ideas in Australia.  Neither advocated boxing these in with wood though. Charles Dowding, an advocate of no dig, says that he is not boxing his beds in any more. 

The French gardeners took hot bed gardening to new levels around Paris during the late 1800s and their methods were brought to Britain by C.D. McKay in his book “The French Garden in England”.  However, they did not use boards to keep the manure from falling into the alleyways.  If you read Abercrombie or Loudon carefully they say use boards to start the hot bed pile but remove them afterwards. 

So there was a tradition of four foot wide “raised” beds with alleys between them way back into the past.  Edging was traditionally a plant rather than wood and these were placed around the quarters rather than the individual beds. 

After the dissolution of the railways, railway sleepers became very easy to acquire and were relatively cheap.  Some people used these to make raised beds to plant rhododendrons, camellias and magnolias after filling them with peat. 

So I think that the wooden raised bed developed from the use of sleepers in flower gardens and the decorative bricks used in retaining walls and raised beds of disabled gardens. 

Furthermore flower garden designers were using more and more wooden containers for patio gardens during the 1980s and these could have just got a little bigger and used for vegetables. 

Now there are many reasons for and against making boxed raised beds but one that has just been brought to my attention is the problem of using treated wood.  Railway sleepers cannot be used in the garden anymore and if you are using them then you should seriously consider taking them out. 

Whereas I am very sceptical of just accepting what it says on websites, they do generate a lot of thought. 

This is one such website. 

Now if you have read any other of my blog musings, you will know that I am not a fan of boxed in raised beds.  However, I never thought of the problem of treated wood being used.  I know that lots of people are using decking off cuts to make their raised beds and this wood will have been treated in some way or other to prevent rotting.  I thought that tanalised wood was made using tannin from oak bark but I was clearly wrong. 

So, I have just bought several tanalised tree stakes to train my espaliered apple and pear trees.  Are they safe to use in the garden?   I’m not at all sure now. 

The debate on Grow Your Own website clearly says that tanalised wood is safe:

Yet I always ask myself why I am growing my own food.  Is it to produce food that is man made chemical free?  If it is why use pesticides?  All that tanalisation is is applying fungicide to garden wood.  I would rather not use wood at all if I could get away with it. Cuz wood rots.  Where I have to, such as the shed, I like to keep it off the soil as much as possible.  My shed is on concrete slabs but how much that will do to keep my allotment safe from tanalising chemicals I don’t know.   

I am trying to make my allotment a little more fungi friendly for at least two reasons.  Firstly I would like to encourage mychorrhizal associations that  benefit most allotment plants.  Secondly, you can eat the fruiting spore producing caps of fungi.   I just need to learn to identify more edible ones. 

Using a lot more woody shredded material as a mulch on the allotment means that I would like to encourage fungi to rot down the mulch during the year and then it can be dug in during the winter months and be replenished with new material in the spring. 

When encouraging wildlife onto the allotment we should not forget the vast fungi kingdom. 

The chemicals in tantalised wood might not do humans any harm at all but they will certainly damage the fungi living in the allotment soil.  What effect they have on other soil life is anyone's guess. 
Now what on earth do I do about the tree stakes?

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