I have sown a deep tray of Leek Musselburgh and put the tray into a polythene bags to preserve moisture and heat. I have grown this variety before with varying success which has more to do with the gardener than the variety. I shall grow them on until they look sturdy enough to plant out on the allotment. They will probably be put into the ground that the potatoes come out of where they will stay until early next year.