There are approximately 600 species of oaks (Quercus) found throughout the Northern Hemisphere from the tropics to the far north.
The group shows considerable variety and many species can be found in our oak collection on Broad Drive.
Here are a selection of oaks to be found at Westonbirt, The National Arboretum. You can find other varieties and locate specific specimens using the Westonbirt Interactive Map.
Pyrenean oak, Quercus pyrenaica
This rare deciduous tree was introduced to Britain in 1822 from southwest Europe. Westonbirt has some fine old specimens planted on Willesley and Waste Drives planted around the 1880s. It is one of the latest oaks to come into leaf in the spring.
Common or English oak, Quercus robur
One of Britain's two native oak species, Quercus robur is the most common one in southern and lowland areas. Together with yew and Scots pine, this large long-lived species often provides the backdrop for the more exotic species in our collection. However, it is a magnificent species well worth looking at in its own right.
It can be found growing throughout the arboretum, although a particularly magnificent specimen can be found close to the junction of Main Drive and Circular Drives. Several veteran trees can also be seen on the Downs and these provide invaluable wildlife habitats for a wide variety of species including little owls and bats.
Kermes oak, Quercus coccifera
At first appearance this small shrubby tree may appear more like a holly than an oak. Its prickly evergreen leaves are the food of the Kermes insect from which the scarlet dye cochineal is obtained. Originating from the Mediterranean, it has been cultivated in Britain since the 17th Century. Specimens can be found in the oak collection in Silk Wood.
Introduced from the Caucasus in 1873, this is a rare species with striking large lobed leaves. It also has stout twigs covered in pale grey velvety hairs. Mature specimens can be found in the Old Arboretum.
Red oak, Quercus rubra
This large, fast-growing species comes from Eastern Canada and America and was introduced to Britain in 1724. It thrives in our damp climate and has been grown in plantation by foresters. Unfortunately its timber is less valuable than that of our native species and it is extremely prone to damage by grey squirrels. Its large lobed leaves are sharply toothed and turn (as its name suggests) bright red in autumn.
Holm oak, Quercus ilex
This Mediterranean species is the most frequently seen of the evergreen oaks. The small glossy leaves are adapted to reduce water loss - vital to the tree’s survival during the hot dry summers in southern Europe. Being evergreen, they can afford to shut down during the summer to prevent water escaping through the pores in their leaves. To make up for this, holm oaks in the Mediterranean grow in the spring, when the soil is still moist after winter, or autumn, after the first rain. Many trees were planted early in the arboretum’s creation and good specimens can be seen in most areas.
Algerian oak, Quercus canariensis
Also known as Mirbeck's oak, this large tree with very dark grey bark is semi-evergreen - often holding its leaves into the New Year, making it easy to recognise through the winter months. A particularly fine tree grows towards the northern end of Broad Drive.
Armenian oak, Quercus pontica
Introduced from northeast Turkey in 1885, this unmistakable tree has large strongly ribbed and toothed leaves that turn a rich yellow colour in autumn. It rarely exceeds the size of a large shrub