Champion trees are the largest trees of their species growing within the British Isles.
Champion trees can qualify either by being the tallest or by having the largest trunk girth (measured at 1.5m off the ground). A register of champion trees is maintained by The Tree Register.
Currently Westonbirt has 80 champion trees - and it's not all about being the largest. Some trees' natural growth form means that they will always be relatively small in 'tree terms', while in other cases the tree may be a champion because its rarity means there are few other specimens growing elsewhere in the country and thus little competition.
A full list is available, but here are four to look out for to get you started (more pictures will be added shortly). Why not use the Westonbirt Interactive Map to locate particular specimens before your visit?
Wingnut, Pterocarya x rehderiana
Native to Asia, the wingnut family comprises of six species of large deciduous tree.
Each has pinnate leaves and characteristic strings of nuts. Each nut has two small wings, hence the family's common name.
P. x rehderiana is a hybrid cross between P. fraxinifolia (Caucasian wingnut) and P. stenoptera (Chinese wingnut). Our champion can be found growing at entrance of Pool Gate and is 25m tall, 434cm diameter (last measured 2002). It is a champion for height.
Lawson’s cypress, Chamaecyparis lawsoniana
This large evergreen tree, regularly reaches 50-70 m (200 ft) tall in its native range - so our Chamaecyparis lawsoniana 'Blue Jacket', located at 20D, still has a way to go. It is currently at 20m high and 126cm girth (last measured in 2008).
The feathery blue-green foliage consists of tiny scale-like leaves each with narrow white markings on the underside.
Bristol whitebeam, Sorbus bristoliensis
The Bristol whitebeam is endemic to the UK and is only found in the Avon Gorge where there are estimated to be about 100 trees.
It is one of a number of whitebeam species in Britain, many of which are threatened in the wild due to their small population size and limited distribution.
Our two champions grow on Broad Drive. The first is 13m tall, 157cm girth and champion for both height and girth. The other is 12m high and 145cm girth.
Date plum, Diospyros lotus
Introduced by Ernest Wilson, the date plum is the only member of the Ebony family we grow at Westonbirt. Again it is quite a small tree. Our specimen can be seen growing in map reference 27F.