Sapium discolor Seeds | Mountain Tallow
LATIN NAME: Sapium discolor
COMMON NAME: Mountain Tallow
Plant Profile
Mountain Tallow is a fast, small deciduous tree of southern China and Southeast Asia, reaching five to ten metres with a rounded crown and leaves that turn brilliant red before they fall. Its small yellowish flowers are followed by three-lobed capsules that split to show white-coated seeds.
It grows on hillsides, forest edges and abandoned ground, colonising open slopes quickly, and in southern China it is one of the trees that makes the autumn hills red. It is closely related to the Chinese tallow tree and shares both that species’s brilliant autumn colour and its irritant milky sap. The branches carry the leaves in flat sprays that show the autumn colour to advantage, and the trunk stays slender enough for a small garden in the right climate.
Science & Biotechnology
Modern treatments place it in the genus Triadica with its better-known relative, the Chinese tallow tree, Triadica sebifera. The family is the spurge family, full of milky-sapped plants whose latex irritates skin and eyes, and gardeners should treat this tree accordingly: a landscape tree, not a browsing one.
Its quick growth on poor slopes has made it a subject in reforestation trials in southern China, where it is used to clothe eroded hills ahead of slower species. Its capsules open by three valves and the white-coated seeds are carried by wind and water along the gullies it colonises.
Uses & Benefits
In frost-free districts it is a fast ornamental for autumn colour, and its red foliage has made it a street tree in parts of southern China. It is not a tree for paddocks, both for the irritant sap and because its seedlings spring up freely in open ground.
In its home range its seeds were once rendered for wax and oil on a village scale, a use the Chinese tallow tree outcompeted it for; today it is grown for slope restoration and ornament. Because it grows so fast in its first three years, it has also been used as a temporary nurse tree, sheltering slower species that take the site over later. Its autumn display pairs well with the maples of the same climate, and the red it gives arrives earlier, extending the season at the front of the colour wave.
Growing from Seed
Sow fresh seed after cleaning away the white seed coat, half a centimetre deep in a warm, free-draining mix at 22 to 25 °C.
Germination takes two to three weeks and the seedlings grow fast; give them full sun and never let them stand in water.
Pot on promptly and plant out young, in full sun and with space to spread, in districts free of frost; elsewhere it makes a large container subject that can stand outside for the summer. In its second year the stem thickens fast, so stake it loosely rather than rigidly, and remove the stake once the trunk carries its own weight. The seeds are heavy and fall close to the tree, so a ring of mulch keeps the volunteer seedlings from crowding the base.
Our Take
A fast autumn-red tree of the southern hills, quick to clothe a slope and quick to tell you it is a spurge: plant it with gloves on.
Related Reading
Gardeners who grow Mountain Tallow often pair it with these related subjects: