With the ever increasing demand for allotments in the London Borough of Ealing, more and more sites are turning empty spaces or dividing up some of their standard plots into raised beds. These can also be used as starter plots for tenants who are new to growing fruit and vegetables. They can gain confidence and experience to enable them to move on to a larger plot when one becomes available, or to decide that gardening is not for them. Higher raised beds can also enable older or disabled tenants to continue to cultivate their own produce. There are also growing benefits using raised beds. They can drain freely if the ground is clay, the growing medium can be kept weed free and soil fertility maintained more easily.
If a site wishes to create a raised bed area then there are some practical considerations for the site manager:
Location: Chose an area which can fit the most raised beds together. This will help build a sense of community and also makes logistics easier. There should be a path of minimum 70cm (2ft 6in) up to 1m (3ft 3in) between each raised bed. The paths can be of grass which will need maintenance or woodchip which is easier to maintain and readily available from local tree surgeons.
Size: They don’t need to be rectangular or square but these shapes are the most easily cultivated. A size of 1.2m (4ft) x 2.4m (8ft) is ideal as it allows all parts of the bed to be reached.
Depth: A minimum of 30cm (1ft.) The higher the bed, the easier it is for older or disabled gardeners to use. Fill them with a cheaper base (e.g. rotted woodchip, subsoil) and top up with the best quality topsoil that can be afforded. Don't fill them right up, but top up annually with compost or well-rotted manure.
There is lots of advice available on the internet. Here are a few links to help:
RHS Raised Beds
5 Materials for building Raised Beds
How to construct raised beds
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