Our expert guest today is one of New Zealand's most notable tree experts. Brad Cadwallader manages the New Zealand Tree Register an online record of all of our finest trees - from the largest red flowering gum in the world, which is in Hamilton, to the tallest Norfolk pine - which is in Tauranga - to trees that have been planted by princes and queens.

Eucalyptus seiberi - silver ash Church Hill Nelson (Image Brad Cadwallader) Measuring trees for the register Atlantic blue cedar planted on the 15th of January, 1954 to celebrate the Royal Visit, planted by Her Majesty Queen Elizabeth II at Government House, Wellington (Image Brad Cadwallader) Her Majesty Queen Elizabeth II planting a tree in 1954 at Government House (image Alexander Turnbull Library Giant sequoia in Milton Otago Populus nigra This tree was planted by the Prince of Wales on a sunny afternoon on the 10th May 1920 at Marlborough Boys College Populus deltoides subsp. monilifera ‘Frimley’ 'The Frimley Poplar' 1969 Frimley Park Hastings. (Photographer S.W. Burstall)