Double the size of the Cambridge Raised Planter to grow even more flowers and vegetables with less weeding, less pests and no soil compaction. The Cambridge Planter Extension will extend the Cambridge Raised Planter to perfectly fit your porch or balcony. The Cambridge Extension cannot be used alone – as it fits with the Cambridge Raised Planter. The Cambridge Extension is strong and durable and will never need to be painted or stained. The occasional rinse with a garden hose is all you’ll need to do to keep your planter box looking great year after year. This product comes with a 20 year manufacturer’s warranty against yellowing, warping, cracking, and rotting.