Taxus cuspidata Seeds | Japanese Yew

Japanese yew with flat dark needles and bright red arils on a branch — Japanese Yew (*Taxus cuspidata*): Taxaceae, mountain forest of Japan, Korea and northeastern China.

LATIN NAME: Taxus cuspidata

COMMON NAME: Japanese Yew

Plant Profile

Japanese yew is a slow, long-lived evergreen conifer from Japan, Korea and northeastern China, where it grows in mountain forest under taller trees. It makes a broad, irregular cone ten to eighteen metres tall, with a short trunk, reddish-brown bark that peels in strips and flat, dark green needles arranged in two ranks along the shoot. Male and female cones sit on separate trees. The seed is a hard nut partly enclosed in a bright red, fleshy aril that looks like a berry and is the only part of the plant that is not poisonous. In Japan it is clipped into hedges and trained as a garden tree, and old specimens in temple grounds are centuries old. The wood is fine-grained, elastic and prized for bows and for carving.

Science & Biotechnology

Taxus cuspidata is one of the sources of paclitaxel, the diterpenoid alkaloid sold as Taxol, and the discovery of that compound in yew bark in the 1960s turned a slow, obscure conifer into an agricultural crop. The concentration in bark is tiny, around one part in ten thousand, which is why early supplies were scarce and why cell-culture and semi-synthesis routes were developed. All parts except the aril contain taxine alkaloids that block cardiac sodium channels, and deaths have followed from eating the leaves or chewing the seeds. Taxus is also unusual among conifers in having no resin canals and in regenerating from buried branches, which is why old trees can spread into clonal thickets. Seed dormancy is deep and double, with an immature embryo and a hard coat.

Uses & Benefits

The wood has been used for centuries in Japan for bows, for the pillars of shrines and for small carved objects, and its durability and fine grain make it valuable out of all proportion to the size of the tree. In the garden it is a first-rate hedge and topiary plant: it takes hard clipping, grows in shade and stays dark green through winter. It is also the species most often used for Japanese-style pruning, since the needles regenerate from old wood better than most conifers. The aril is eaten by birds, which disperse the seed intact, and the dense foliage gives winter cover for small birds. Every part of the plant is toxic to people and livestock, so it belongs away from grazing and away from children’s play areas.

Growing from Seed

Clean the aril off the seed, then give it warm followed by cold: three months at twenty degrees in damp sand, then three months at four degrees. Sow in late winter in a peaty, free-draining mix, one seed per pot, one centimetre deep. Germination is slow and can take two seasons. The seedlings are extremely slow, adding a few centimetres a year at first, and they resent root disturbance, so pot on sparingly. Grow in shade or half shade with moist, acid soil. Plant out in autumn with the root ball intact, mulch with leaf mould, and water through the first two summers. Do not clip until the third year.

Our Take

Slow, dark and dangerous, and one of the best conifers for a shaded hedge. Keep the secateurs and the gloves on.

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