Great oaks and little acorns in Sidmouth Arboretum

Turkey oak at Knowle (Image: Archant)

Thanks to Victorian and Edwardian landowners, Sidmouth has many mature trees and the park and gardens around Knowle, in Station Road, are home to some of the finest and are well worth a visit.

This month I want to introduce the oak trees in Knowle.

There are approximately 600 different oak species and Knowle is home to six of them: English, Sessile, Turkey, Red, Pin and Holm Oaks.

Holm Oaks are easiest to pick out because they are evergreen, with dark green leathery leaves that look a bit like bay leaves. Leaves on young Holm Oaks have small prickles, hence the scientific name Quercus ilex, which means Holly Oak. There is a magnificent pair of Holm Oaks in the lawns area of the Byes and a large one in Powys which faces you as you walk out of Knowle Drive onto Station Road.

Turkey oak acorn (Image: Archant)

There are several English Oaks in Knowle, ranging in age up to about 200 years old. One of two native species, the English Oak is a haven for wildlife from nesting birds to leaf-eating caterpillars. The leaves are the classic lobed oak tree shape on very short stalks. A distinguishing feature is that usually there are two small lobes pointing back down the stalk. The English Oak has an alternative name, the Pedunculate Oak, because its acorns are carried on stalks.

The other native species is the Sessile Oak. Sessile means without a stalk and this refers to the acorns which, unlike the English Oak, are produced very close to the twig. However, the leaves have longer stalks than those of their Pedunculate cousins, also they do not have the small backward pointing lobes at their base. Sessile Oaks are much rarer than English Oaks and the only one I can find in Knowle is a youngster aged about 50-70 years that stands by Balfour Lodge.

The largest tree of any type in Knowle is a huge Turkey Oak that stands inside the double gates on Station Road near the concrete base once used for Sidmouth Folk Festival. At a height of thirty-four metres (110 feet) and with a trunk diameter of nearly two metres, this tree is about 250 years old. I defy anyone to stand under this majestic canopy and not to have a sense of awe. There is a smaller one which has very interesting, deeply cut leaves in the shrubbery behind the large Monterey pine in the garden of Knowle.

Turkey Oaks can be distinguished by their acorns which take eighteen months to mature and have a hairy cup. Unfortunately, the Turkey Oak is host to a gall wasp the larvae of which damage the acorns of native British oaks.

Turkey oak acorn (Image: Archant)

On the western side of the park and walk car park is a large Red Oak. It is called a Red Oak because, in its native North America, its large leaves with their pointed lobes turn a glorious red in autumn. Disappointingly, they tend to just go rusty brown in the UK climate, but this is still a substantial tree. There are several younger ones around the park.

The sixth species of oak in Knowle is the Pin or Spanish Swamp Oak. This has very deeply cut leaves which put on a good show of autumn colour. There are two beside the large Red Oak, another at the top of the large bank facing Station Road, and a third is struggling amid the brambles and rhododendrons as you enter the gardens at the southern end of Knowle Drive.

You can find out more about the trees in Knowle on the Sidmouth Arboretum website https://sidmoutharboretum.org.uk and the Arboretum’s Town Trail walk takes you through Knowle.

Oak leaves (Image: Archant)

Red oak at Knowle. (Image: Archant)

Holm oak in The Byes (Image: Archant)

Holm catkins (Image: Archant)

Turkey oak acorn (Image: Archant)