A woman and a man tipping manure into a raised bed from a wheelbarrow

Raise a cheer for raised beds!

Why do we want all this grass? It was a good question. We had various ideas for developing our community garden, but little did we realise that this question – posed by a knowledgeable horticultural visitor – would lead to an extensive programme of sustainable change!

We reduced the expanse of grass – and created larger beds for growing our veg. Our allotment opportunities became more extensive – and we became more ambitious. We weren’t entirely sure where we were heading, but ideas were starting to seed, and conversations began about raised beds, sources of wood to build these, and possibilities for soil enrichment.

We were keen to tap into the natural resources around us – the fields and woodlands on our doorstep as well as the local community of farms and stables.  And being part of a charity that has upcycling as a core activity means we are always on the look-out for cost effective development opportunities.  Our outlook tends to be – ‘if we can, then we should’.

Many raised beds are constructed from sleepers. These are sturdy and durable, but they are expensive – increasingly so. We looked for alternatives and sourced some reclaimed wood – from Butlin’s stage no less – at a cost of £6 per plank! We remain intrigued as to who might have trodden those boards in years gone by.  

Building a number of raised beds provided an opportunity to explore how best to preserve the Butlin’s wood.  We wanted to experiment – to make them last as long as possible using methods that are kind to the environment – to the soil and to the plants that grow inside. 

We discovered plant friendly wood preserver as a start point – we used this to coat the wood for our first raised bed.  Further research led us to linseed oil. We know you can’t use boiled linseed oil as it has been through a chemical process (not plant-friendly), but you can used raw linseed oil instead as a wood preservative. We applied this to our second raised bed.

We looked for more options and came across ‘Shou Sugi Ban’ – an ancient Japanese wood charring technique. Heat from a blow torch is used to scorch the surface of the wood, turning it black. A layer of carbon forms and the oils within the wood are drawn to the surface – leading to a natural preservation effect. The wood for our third raised bed is now suitably charred – the blackened surface beautifully highlighting the natural grain.

Like any good research, there should be a ‘control’ – so the wood of our fourth raised bed is in its natural state so we can compare how it fares over the following years.  

We have also been experimenting with soil enrichment for our beds – looking at different ways of reducing or improving the environmental impact at each stage of the process. The soil we started with at the site was very poor – we need a lot of soil improver.  We started by collecting this from local farmers – which gave us good quality, well-rotted manure. We then discovered a soil improver made locally at Ashlyn’s Farm from their green waste – this is also free of charge so we began to collect this too.

Mindful that we were bringing in a lot on our truck, we contacted Chigwell Riding Trust at the end of our lane and collected their manure at the same time.  This is the ideal source for us – far shorter truck journeys using as little fuel as possible, with the hope of becoming self-sufficient in creating our own soil improver. We’ve now started this process by putting the fresh manure in clamps that we made from recycled pallets – this will break it down over a couple of years. We regularly top this up using the stables next door as our main source, as well as leaf mulching – which we collect from around the grounds of our site.

We are aware that there is much talk in the gardening community of the ‘no dig’ approach to maintaining soil quality – i.e. not turning the soil over. There is a trend towards this in farming as it doesn’t destroy the soil structure – soil microbes are allowed to develop and the carbon is left in place rather than releasing it into the atmosphere. Our plan is to use the compost that we’ve developed to operate a no-dig trial in future – filling the beds and revitalising them but without digging them up. This will also be less work!

We would also like to trial ‘Hugel Kulture’ – which is an approach to filling the beds using different materials to reduce the amount of topsoil required – meaning we don’t have to import as much. The base layer of the bed is formed using cardboard, with wood and sticks on top of that, followed by a thin layer of leaves and garden waste, then a layer of compost, finished with soil on top. The soil comprises 30% of the total bed.

We are looking forward to seeing the results of our work so far, and continuing to experiment in ways that maintain and preserve the natural resources available to us. We are learning as we go – as a team. The details are important in conserving what we have – and everyone is benefiting from an increased understanding of these. Soil is key, and we need to treat it well to maintain a sustainable way of growing our food.

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