Turner's oak

Quick facts

• Scientific name: Quercus x turneri
• Family: Fagaceae
• Place of origin: this tree is a cross between the English oak and the holm oak. It was created in the Essex nursery of Mr Turner in 1783 – though it didn't get properly named until over 100 years later.
• Conservation status: Least Concern
• Date planted: this tree was raised in Mr Turner's nursery before being planted in Kew's original 5 acre arboretum in 1798.
• Height: 20 m. This is a good size for this species, which tends to be smaller than other oaks.

About Kew's Turner's oak

On 15 October 1987 a great storm hit the UK and felled around 15 million trees nationwide. It lifted this tree’s root plate right up, then resettled it back down. But unusually, this didn’t kill the tree.

Before the storm the tree had shown signs of stress, its roots having become compacted by people sheltering under it for years. Afterwards it had a new lease of life – its roots had been 'decompacted' and had more space, air and water to help it grow. Seeing this, Kew’s staff quickly developed decompaction methods for use on other trees. This involves injecting nitrogen gas underground using an 'Airspade'. It works – trees show improvement a year after treatment.

Take a closer look

• The leaves of this hybrid are similar in colour to other oaks, but their shape is different. Rather than the familiar rounded lobes of the English oak, look for almost sharp, forward pointing teeth on its leaves.
• The metal struts supporting this tree were put in soon after it was almost uprooted in the great storm of 1987. They were placed to support the branches while the root system was recovering. Today they may not be needed but they are so firmly in place we have not removed them.

Tree biology

Compared to some oaks, Quercus x turneri is relatively small, growing to around 17 m in height. It is a popular ornamental plant because of its tendency to hold on to its leaves until just before new growth comes in the spring. In very severe winters it does lose its leaves, usually between February and April. But it is, essentially, one of just a few semi-deciduous oaks.

Cultivation and uses

Turner's oak is a cross between Quercus robur (the English oak) and Quercus ilex (the holm, or holly oak), creating a hybrid with lobed oak-like leaves and an evergreen habit. This makes it a popular choice for ornamental planting. Its low shape and twisting, horizontal branches which can just skim the ground, also make it a popular choice with tree climbers.