Ribbed planters are of traditional 17th century design. There used to be a very good example
in the garden of No 10 Downing Street, dated 1666. There are six standard sizes in this range,
pictured immediately below. In each case the face of the planting container is divided into little
squares, and these squares should be regarded as building blocks, to be added to or
substracted as desired. The further pictures illustrate how this works, giving rise to planters of
almost any size or shape.