With the festive season in sight David heads to a Christmas tree farm to see some of the most popular varieties and find out how to look after living trees during the festivities. In Killinchy, Ann Fitzsimmons is planting Christmas Box and species tulips that will perform year after year. Johnny Knox gives David some winter garden design advice and Claire McNally is taking questions live and a listener reveals the results of his fermented nettle experiment! Contact the programme on gardenerscorner@bbc.co.uk