Onion Sets - Sturon RHS Award of Garden Merit Winner! The Onion - Sturon is a well known onion variety, renowned for its flavour. The Sturton onion set produces round, straw coloured onions that are plump and medium in size. Perfect for any meal you wish to add them to. The onion - Sturton will keep well through the winter due to its thin neck, meaning it will remain in great condition right through until February/ March time.  Being an RHS Award of Garden Merit Winner, the Onion set - Sturton is a true must have to grow in your garden or allotment.