Xanthoceras sorbifolium Seeds | Yellowhorn
LATIN NAME: Xanthoceras sorbifolium
COMMON NAME: Yellowhorn
Plant Profile
Yellowhorn is a large deciduous shrub or small tree, 3-8 m, with pinnate leaves of nine to seventeen leaflets and clusters of white flowers in late spring. The fruit is a leathery capsule that opens to reveal round black seeds, and the seed is edible and oil-rich.
The plant is grown as an ornamental for its flowers, which open before the leaves and cover the branch tips in May, and as a crop in China for seed oil. It is drought tolerant, tolerant of poor soil and hardy to about -25°C, which makes it a useful plant in continental climates.
Xanthoceras sorbifolium comes from northern China and Korea, where it grows on dry hillsides and is cultivated for oil and for medicine. It is the only species in its genus, which makes it a botanical curiosity as well as a useful plant.
Science & Biotechnology
The seed contains 55-70 per cent oil, rich in oleic and linoleic acids, and the oil has been studied as a biodiesel feedstock in China, where plantations have been established on marginal land. The cake left after pressing contains saponins and is used as a fertiliser and a molluscicide rather than as feed.
The leaves and fruit contain saponins and flavonoids, and extracts have shown antioxidant and anti-inflammatory activity in laboratory studies. The seed is edible after roasting, and the taste is described as resembling a sweet chestnut or a pine nut.
Yellowhorn is one of a small number of woody plants that flower on one-year-old wood and fruit within three or four years of sowing, which is fast for a tree grown for oil. That precocity is one reason it is considered a promising crop for marginal land.
Uses & Benefits
The plant is grown as an ornamental shrub for its white flowers and its yellow autumn colour, and as a crop for seed oil. The seed is eaten roasted in China, and the oil is used for cooking and for industrial purposes.
In the garden it suits a dry bank, a windbreak or the back of a border, where its early flowers are a valuable nectar source. Commercially the seed is sold to growers interested in oil crops and to nurseries in continental climates. The wood is hard and is used for small implements in its native range.
Growing from Seed
Sow in autumn or stratify for twelve weeks at 3-5°C before spring sowing. Sow 2 cm deep and germinate at 18-22°C; germination is slow and uneven. Fresh seed gives the best results.
Plant out in full sun in well-drained soil. The plant tolerates drought and poor ground but needs good drainage, and it dislikes transplanting once established. Water through the first two summers, then only in severe drought. Prune after flowering if a shape is needed, since the flowers are borne on the previous year’s wood. Seedlings can spend two years in a nursery bed before they are moved to their final position.
Our Take
A flowering shrub that also produces an edible oil seed, and one of the few ornamentals that would earn its place in a working garden.
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