Plant of the Month

Plant of the Month for January
Thuja occidentalis ‘Rheingold’

Thuja occidentalis ‘Rheingold’

This is a superb example of a dwarf / slow growing conifer – Thuja occidentalis ‘Rheingold’ (AGM). It is a plant which has been available for over 100 years to gardeners in this country, awarded the RHS Award of Merit in 1902 and subsequently the Award of Garden Merit in 1969. It is a member of the family Cupressaceae and is one of a number of colourful cultivars of the species Thuja occidentalis which originates from eastern North America.

Thuja occidentalis ‘Rheingold’ is a lovely garden plant for adding all year round interest. It is ideal for planting as a dwarf conifer in a Heather border where it will reach only one metre in height after ten years growth. Alternatively it makes a lovely addition to a gold themed border with its finely patterned foliage, with two distinct types being produced, juvenile when young, small and feathery, and adult scale-like foliage as the plant matures. It will also perform well as a specimen plant for a terrace or patio, grown in an ornamental container, often of a contrasting colour.

The plant can produce either a rounded evergreen shrub or be of a more conical shape. It is evergreen but reaches its most spectacular in the middle of the winter months when its golden yellow foliage turns a rich coppery gold on the prominent branches. The foliage is ideally suited for inclusion in seasonal decorations such as florists’ floral holly wreaths to decorate the home.

On Myerscough Gardens Thuja occidentalis ‘Rheingold’ can be seen as a thirty year old specimen by the Garden Tea Room outside the Cactus display glasshouse, where it was formerly part of a Gold Border. Unfortunately it has been left in isolation as it was too old and large to move to the new border but a young specimen has recently been planted in the Heather and Conifer border, where other mature cultivars (Holmstrup’s Yellow, Marrisen’s Sulphur and Sunkist) can also be seen.

Thuja occidentalis ‘Rheingold’ could be used to make a semi-formal hedge if planted in a single line but a more suitable Thuja for a tightly-knit hedge is Thuja plicata (known as Western Red Cedar), from western North America. This is a faster growing, taller and more robust conifer which will withstand cold winds and pruning without scorching.

Its shiny green foliage has a highly fragrant, resinous nature, smelling like pineapple when crushed. This species is used as a tall, thick hedge to provide shelter for the production glasshouses at Myerscough but can also be seen as a specimen tree in the Pinetum along with its yellow variegated cultivar ‘Zebrina’.