The materials used in the construction of a raised planter will determine its functionality and life span. Wooden raised planters look good when bought new, but rapidly tarnish and split. Early planters were prone to rot rapidly, but this has been addressed to some extent by the use of timber preservatives (although these now have the potential to leach into the soil!) The majority of wooden raised planters are manufactured in China and imported flat-packed for home assembly. These planters require the internal liner to be replaced every two years, requiring it to be fully emptied each time! A major drawback of the trough design is that the maximum soil depth is only achieved in the central third of the planters, tapering substantially to each side, and severely diminishing its effectiveness!
Planters manufactured from plastic are, in theory, more durable than those made of wood but this depends on the type of plastic used, its thickness and the moulding technique employed. Those manufactured from black polypropylene have a wall thickness of 1.5-2.0 mm and are injected moulded. While the use of UV stabilisers slows their deterioration, they are still prone to become brittle and crack - particularly at corners. These raised planters typically incorporate a capillary irrigation system. While this may work well in hot climates, it is less successful in temperate conditions and is liable to produce very uneven gradients in moister content within soil, preventing full and efficient rooting.
The poor design and quality of raised planters manufactured in China is unfortunately typical of the UK garden sector, which has an unenviable reputation for marketing products with a short life span, which are considered disposable in every sense and cannot be recycled at end of life. Ergrownomics have dared to produce a raised planter with a 40-year design life and which - moreover - can be widely recycled at end of life. These requirements have been met by opting to use MDPE which is a ‘food safe plastic’ (certified by the Food Standards Agency), and adopting rotational moulding to manufacture the containers. The plastic used and process are identical to those used in the manufacture of life-buoys which have proved extremely durable in marine environments. Recognising the concerns that some people have with the use of plastic, Ergrownomics also offer a container manufactured using 100% recycled MDPE. Ergrownomic planters are also fully inclusive of the frame, manufactured using heavy duty steel clamps and fittings (galvanised twice)! Set screws in the clamp are also stainless steel, further evidence of a desire to ensure the long-term serviceability of the product, and preserve the option of disassembly. To ensure these high standards, our planter is entirely manufactured in the UK, also helping to minimise the environmental impact!