Arborvitae
This is a genus of five species of which Burncoose stocks a few forms of only two. Thuja are completely hardy evergreen conifers whose common name gives a fair idea of how fast the species grow. That is not to say that dwarf growing forms have not been bred which are not fast growing at all and make good rockery or even shrub border plants.
Thuja plicata is an excellent windbreak hedge and can be clipped and trained into a formal hedge with some difficulty for a limited number of years before the trunks simply get too big. When a freak whirlwind hit Burncoose garden in 1978 the front drive was blocked with fallen trees for six months and no mature trees at all were left in the centre of the garden. Within 20 years a row of T. plicata was up and running. Today it is 60-70ft tall and by no means finished growing yet. In places we grew two rows and have recently had to remove one to give space for the others to grow. Other windbreaks have been established in the meantime and another whole row was also felled. However, there is no doubt that this American tree has a firm place in creating a tall, quick growing, windbreak tree. It is rather nicer to look at with its more mature pendulous branches too than x Cupressocyparis leylandii.
T. occidentalis ‘Rheingold’ is a conical bush growing slowly to 3-6ft in height. It has golden-yellow leaves which are pink tinted when young and makes a good feature plant if grown on its own or in the back of a border.
T. plicata ‘Whipcord’ is a most unusual dwarfish conifer that the author first saw growing near the entrance to the Savill Garden in Windsor. It has now become established in the garden at Caerhays beside a path as you can see in the pictures below. It is a mounded shrub with pendulous whipcord-like foliage which can go bronzy in a cold winter.
T. plicata ‘Zebrina’ is a conical tree growing up to 30-40ft. Sprays of its foliage are banded with creamy-yellow. Possibly one of the best variegated conifers for visual effect since the variegations are often so crowded that the whole tree looks yellow.
