'unplantable' originates from the prefix 'un-' meaning 'not' and the word 'plantable', which comes from 'plant', meaning 'to place in the ground to grow'.

'plantable' changed from the Old English word 'plantian', which meant 'to plant', and eventually became the modern English word 'plant'.

Initially, 'plant' meant 'to place in the ground to grow', and 'unplantable' evolved to mean 'not suitable for planting'.