Pittosporum tobira aka Australian Laurel

Japanese pittosporum, Pittosporum tobira, is a broadleaved evergreen shrub or small tree in the family Pittosporaceae. It is native to southern Korea, southern and central Japan, the Ryukyu Islands, Taiwan and parts of China. In the wild it grows on coastal rocky hillsides, sandy shores, limestone slopes and forest edges. Other common names include mock orange, Australian laurel and Japanese cheesewood.

In gardens it forms a dense, rounded mound, sometimes with a vase shape. Most plants reach 8 to 13 feet (2.5 to 4 m) tall. Older shrubs may reach about 15 feet (4.5 m). Width varies widely between sources, from about 5 feet (1.5 m) to as much as 18 feet (5.5 m). Young plants grow fast, but growth slows with age. Stems are often multiple and clumping, with gray-brown bark marked by warty lenticels.

The leaves are leathery, glossy and dark green, and paler and dull beneath. They are obovate, 1.5 to 4 inches (4 to 10 cm) long, with smooth edges that roll under. They crowd toward the shoot tips in whorl-like groups. Leaf edges curl further when the plant is stressed.

In spring, clusters of small five-petalled flowers appear in terminal umbels. They open creamy white and fade to yellow. Their strong scent resembles orange blossom, and they draw butterflies. Sources place flowering from March to June, peaking in late spring. In autumn a small pear-shaped capsule ripens from green to brown. It splits to show red or orange seeds set in sticky pulp.

The shrub grows in full sun or part shade, and some afternoon shade helps in hot regions. It accepts sand, loam, clay and chalk, and both acid and alkaline soils. Good drainage is essential, since wet ground leads to fatal root rot. Established plants tolerate drought, heat and salt spray, which suits coastal sites. It is hardy in USDA zones 8 to 10 or 11. In the UK it is rated H3, so it suits mild and coastal areas with shelter from cold winds. Elsewhere it does well in containers brought under glass for winter, or as a houseplant in bright light.

Gardeners use it for hedges, screens, borders, mass plantings and windbreaks. It takes hard pruning and can be trained into a small multi-stemmed tree near a patio. Flowers form on old wood, so frequent shearing removes the bloom. Prune after flowering to keep the display. Seed or semi-hardwood cuttings propagate it.

Serious problems are rare, but several pests can attack it. Aphids, scale insects, mealybugs, whiteflies and root-knot nematodes all occur. Spider mites trouble the foliage in dry climates, and pittosporum sucker appears in the UK. Diseases include leaf spot, bacterial blight, powdery mildew, crown and root rot, and rarely honey fungus. Deer often browse it. On high-pH soils, micronutrient deficiencies can yellow the leaves.

The ASPCA lists it as non-toxic to dogs, cats and horses. It has no known food or medicinal uses. The plant contains saponins, which are poorly absorbed by people but harm fish.