Stone pines produce the European type of pine nuts used in pesto of which millions of kilograms are harvested every year in the Mediterranean.
About Kew's stone pine
In its early years this tree was kept in a pot as there was no space left for planting in the original five acre arboretum. The tree became stunted and bonsaied so that by the time a further 45 acres was added to the arboretum and it could be planted out, it grew in an unusual shape.
After it lost a limb in a snowstorm in 1926 it began to tilt – so we propped it up. In spite of its colourful history it is a healthy tree and is going strong at over 160 years old.
Take a closer look
- Stone pines produce resin – a sticky liquid that can spill out of splits in the trunk fast enough to engulf unwary insects. Can you see signs of resin leaking out of this tree?
- A normally-shaped stone pine would have its leaves high up in an 'umbrella' shaped canopy, but this tree's early history gave it an unusual shape. This means the leaves are low enough for you sniff the strong pine oil smell that is characteristic of this family.
The stone pine is probably native only to Portugal and Spain, but its tasty nuts mean it has been cultivated and established much more widely. It grows well on coastal dunes and flats, and on the lower slopes of hills and mountains.
The cones can release up to 100 seeds apiece, which they do in response to heat. Sometimes this happens in very hot weather but also after a wildfire – when the ground plants have been burned, clearing the way for new pines to germinate.
Unfortunately it is usually too cold in the UK for our trees to ripen seeds, so we have no pine nut harvest.
Cultivation and uses
20 pine species produce edible seeds known as 'pine nuts' but the stone pine produces most of Europe's harvest. Its cones take three years to mature – longer than any other pine.
The resin contains turpentine, which is used as an antiseptic and to treat skin conditions. The resin also yields rosin, which is rubbed on violin bows and the soles of ballet shoes for grip.
A green dye is produced from the stone pine’s needles, and its wood is used in furniture making. It's a great all-rounder!
- Scientific name: Pinus pinea
- Family: Pinaceae. Of a dozen or so members of the pine family now found in Britain, the stone pine, or 'umbrella pine' as it is sometimes known, is one of the most easily recognised.
- Place of origin: Mediterranean
- Conservation status: Least Concern, thanks to thousands of years of cultivation for its seeds. This species is considered an invasive species in South Africa.
- Date planted: 1846. These trees can last 300 years, so this one is middle-aged.
- Height: 15.4 m