The Oak Collection, Woburn Park

Greensand Country Heritage Trees

You are standing within a collection of oak trees, known as a Quercetum, a collection of trees of the genus Quercus. There are some 530 different species of oak found throughout the world, the majority are evergreen whilst only two deciduous species are native to the British Isles. Although many of these trees may not look like a typical oak the one thing, they have in common is their seed, acorns supported in a cup.

Not all of the trees here have been identified but there are at least ten different species, all from the eastern side of North America. In the Woburn Abbey archives there is a document describing a collection of acorns being received in the 1920’s. These were grown in nurseries on the estate and later planted out, we believe, in the early 1930’s.

There is great variety of leaf shape amongst these trees, varying from that of a typical oak with lobed teeth to those that are narrow and willow-like in appearance with no lobes or teeth and others may be a mixture in-between. If you are visiting in the winter, you will see some of the trees are semi-evergreen. The ones with willow-like leaves belong to the Willow Oak (Quercus phellos) and the largest here is the Bedfordshire county champion. Another champion is a fine-looking tree
behind and nearest you, by the edge of the park, with a broader toothless leaf which is the Shingle Oak (
Quercus imbricaria). The common name refers to the use of its timber for shingle roofs by early settlers in America. Oaks are gregarious and hybrids readily occur in the wild and in botanic gardens. Quercus x heterophylla is a naturally found cross between the Red Oak (Quercus rubra) and Willow Oak and Quercus x schochiana a cross between the Pin Oak (Quercus palustris) and Willow Oak, usually colouring well in autumn, and both are represented in this collection.

The most vigorous of all American oaks is the Red Oak (Quercus rubra), found as a large tree throughout the Woburn Estate but its autumn colour rarely lives up to its name. The best of the oaks in this collection for autumn colour is the Pin Oak.

There is a group of these behind you, and near the roadside hedge. These are the most reliable and should be most obvious by their fiery red and orange foliage. Others will give good autumn colour in their native USA but need more heat and less cold winds to do so here in Bedfordshire.

These trees are providing us with useful evidence on the performance of these species and those that may be more appropriate for planting in the future with a changing climate. Measurements of these trees over the past 30 years confirms the very slow growth rate of some that are clearly unsuited to the Bedfordshire climate. However, together they form a nationally important botanical collection.

The Heritage Tree post has been installed with kind permission of the Duke of Bedford.