Pinus bungeana aka Lacebark Pine

Lacebark pine, Pinus bungeana, is an evergreen conifer in the pine family, Pinaceae. It grows wild in northern and central China, including Inner Mongolia. It has also been introduced to Korea. The species name honours the Russian botanist Alexander von Bunge, who collected the first specimen.

This is a slow-growing tree. In gardens it reaches 30 to 50 feet (9 to 15 m) tall and 20 to 35 feet (6 to 11 m) wide. The RHS notes that wild trees may reach about 100 feet (30 m). Young plants look shrubby. Older trees often carry several trunks and a pyramidal to rounded crown. With age the crown opens out and may become flat-topped. You can also train the tree to a single trunk.

The bark is the main attraction. Young trunks are smooth and grey or grey-green. After about 10 years the bark starts to shed in thin patches. It reveals a mosaic of cream, olive, purple, silver, brown and green. Very old trees turn a milky white. Removing the lower branches puts the bark on display. The stiff, sharp needles grow in bundles of three and measure 2 to 4 inches (5 to 10 cm) long. They are medium to dark green with a glossy, almost waxy look. Bruised needles smell of turpentine. Each needle stays on the tree for two to four years.

The tree is monoecious, so each plant bears both male and female cones. Its yellow pollen cones appear in spring and have little ornamental value. The seed cones are yellowish-brown and egg-shaped, about 1.5 to 2.5 inches (4 to 6 cm) long. Each cone scale ends in a short triangular spine. The seeds are small and winged.

Lacebark pine needs full sun, though it tolerates light shade. It grows in clay, loam, sand or chalk, provided the soil drains well. It accepts acid, neutral or alkaline soil. Once established, it copes well with drought. It is hardy to USDA zone 4 and rated H5 in the UK. It dislikes summer heat and may struggle in zones 7 and 8. Deer tend to leave it alone.

Gardeners use it as a specimen or accent tree near a patio, where people can see the bark. It also suits bonsai. Imperial moth caterpillars feed on the foliage. In Korea people use the timber and eat the seeds and their oil. The seeds are oil-rich with a resinous taste, eaten raw or cooked. Pine wood, sawdust and resin can irritate the skin of sensitive people.

The main weakness is brittle wood. Heavy snow and ice can snap limbs and split multi-trunked specimens. Serious pest and disease problems are rare. The RHS lists adelgids, conifer aphid, sawfly larvae and pine shoot moth as possible pests. Honey fungus and needle cast diseases can also occur. Plants can be costly and hard to find.