Plants of the week- October
Our team are always on the look out for new developments in the gardens. Each week, our Living Collections Manager, Graham, will be sharing some points of interest with us.
The sole survivor of seven trees planted on the Wee Garden’s bank 196 years ago our Quercus suber, common name cork oak, is a southwestern Europe and northwestern Africa native. It’s an evergreen with admirable longevity; a specimen in Portugal is listed in the Guinness Book of Records as the tallest and oldest at 16m in height and 234 years old. Our tree, although only 9m tall, is thought to be the most northerly outdoor specimen in Europe and features characteristic textured bark.
Commercial Quercus suber plantations provide the raw cork product for a wide variety of purposes – bottle stoppers, insulation panels, floor and wall tiles, sound-proofing, cricket balls’ cores, badminton shuttlecocks and fishing rod handles but ours is for visual appreciation only.
Looking at our tree in situ it’s remarkable to think that it was planted at the time of the first gold being discovered in Australia, the game of rugby being founded at Rugby School and the founding of Raffles Hotel in Singapore; if only plants could talk what stories could this one tell!
Colletia hystrix is a slow growing deciduous shrub of the family Rhamnaceae (buckthorns) from Argentina and Chile which, although almost leafless, carries many vicious 4cm long spiny thorns leading to its common names of the Crucifixion Thorn and Barbed Wire Bush. Botanically speaking spines are modified leaves and thorns are modified branches, so technically the very sharp parts of the plant are thorns, designed to keep animals at a distance.
In autumn Colletia hystrix produces a mass of white flowers from rose-pink unopened buds which are perfumed with a marzipan-like fragrance highly attractive to butterflies.
The Crucifixion Thorn is unusual in that it’s one of a small group of non-leguminous plants with the ability to fix nitrogen in the soil making it ideal for planting in poor soil although our well drained soil in a sunny Wee Garden location suits it well too. Frost-hardy, it can grow to 4m in height, ours is 2m and was planted in 1994.
As the nights draw in our chosen plant this week is from the central Andes of South America, Luma apiculata, or the Chilean myrtle, a plant whose particular appeal is its bark – smooth but twisted and contorted which once peeling gives a bi-tonal appearance in rich cinnamon and cream. It’s a vigorous, bushy, evergreen shrub with clouds of fragrant white flowers from July to October, important for honey production in its native Argentina and Chile.
Whilst tolerant of most soil types and conditions Luma apiculata won’t survive in a shaded spot, preferring an aspect with good sunshine to produce edible black or blue berries which ripen in early autumn. Our specimen is located in the north west corner of the Wee Garden. In the UK Chilean myrtle has received the RHS’s Award of Garden Merit and has been naturalised in western Britain and Ireland and also trained in bonsai styling. At full maturity at around 20 years it can reach 4m in height.
Its leaves are used in Mapuche natural medicines to inhibit blood clotting and in the treatment of gastric problems and it’s been the subject of several human clinical trials.
Currently providing a riot of autumn colour in the Rock Garden Cornus controversa is a very slow growing shrub native to China, Korea, the Himalayas and Japan and introduced to the UK in the 1880s by Veitch’s Nursery of Exeter. Our specimen was planted in the 1970s and is 5m tall. This highly attractive member of the Cornaceae family is also known as the wedding cake tree due to its distinctive, horizontal, tiered habit which resembles the layered tiers of a cake.
Considered moderately difficult to grow Cornus controversa likes to be in a sunny or partially shaded spot on well drained fertile soil. In summer it produces clusters of tiny white flowers in panicles, followed by black coloured fruits, but it’s at its best in autumn when its ovate dark green leaves turn this distinctive and showy bright red.