Onion Setton (Spring planting) The Onion Setton (Spring planting) is a fantastic hardy bulb that is easy to grow and care for. Originally created as an improvement from the popular variety ‘Sturon’, it does not disappoint with its more uniform shape, better storage potential and higher yields. Onion Setton (Spring planting) is best grown in a kitchen garden, it will enjoy a position in direct sunlight where it can thrive. This excellent Allium cepa is an RHS award of garden merit holder, its delicious flavour and superb skin quality maintain its popularity.