Western Yew – Taxales Taxaceae Taxus brevifolia


Identification & Description:
Taxus brevifolia, popularly known as the pacific or western yew, is a coniferous tree which inhabits the temperate rainforest of the Pacific Northwest.. The trunk features either a straight or contorted shape and is comprised of a heavy and resistant wood. The trunk sometimes resembles a series of trees fused together, this characteristic is known as fluting . The pacific yew’s bark is delicate and thin ranging from .5-.7 cm in width. Its scaly bark has a reddish brown color whereas its outer bark has a purplish tone . The yew’s slender branches droop creating a weeping appearance . The yew posseses relatively small evergreen leaves ranging from flat to slightly curved with pointed tips that are spirally arranged. Needle size ranges from 1.2-2.6 cm in length and are approximately 1/8 inch in width . The top side of the leaf is a darker green whereas the bottom is a paler yellow-green color. The yew retains its leaves for approximately 3-5 years and in rare cases can keep its leaves for ten years. Its’ wood is composed of dead empty tubes called tracheids which are linked together and make up 90-94% of the tree’s volume. Tracheids provide an essential route for water passage and serve as a crutch to hold the tree in place . The remaining 6-10% of the wood is comprised of rays, sheets of living cells that run along the radii of the wood. The Pacific yew generally lives 200 to 300 years, although some specimens have lived in excess of 400 years. The alkaloids in the yew are extremely poisonous and cause neurological damage resulting in convulsions, muscle fasciculation and paralysis . The foliage, bark, and seeds of most Taxus species are toxic due to the presence of taxine, an alkaloid, however, taxine does not appear to be present in Taxus brevifolia.

The western yew can grow 20 metres high and live a few hundred years. This native North American tree grows primarily along the Pacific coast. It grows in the understory of coniferous or broadleaf stands.

Its fruit is special in that it is the only conifer with a fruit consisting of a red aril around a deep blue seed. All other conifers have cones. Birds can eat the aril but not the poisonous seed.

Other parts of the western yew are toxic for animals. The needles, for example, are poisonous for horses and livestock, but not harmful to moose, deer and wapiti.

Western yew wood has been used to produce certain types of objects. In the Middle Ages, for instance, bowmen used it to make their bows, and today it is used to make paddles and tool handles.

The most prized part of this tree is a medicinal substance called “Taxol” that is found in the bark, needles and twigs. This substance is used to treat cancer.

Unique Features
• Taxol, which is used in some cancer treatment, is derived from the bark of the western yew
• Food for elk, deer, moose, caribou
• Food for elk, deer, moose, caribou
• Square shape in young trees becoming more coneshaped with age
• Branches spread horizontally, or sweeping downwards, trunk is twisted

The Pacific Yew has a continuous distribution on the West coasts of the United States and Canada. These trees inhabit Southeast Alaska, Montana, Oregon, Washington, Idaho and Northern California in the USA and are found in British Columbia and the Alberta Rockies in Canada. They occur with greater frequency in the Coast Range in southern Oregon and northern California while isolated occurrences are found as far south as Marin and San Mateo County. The Yew extends through the Klamath Mountains, the western slopes of the Sierra Nevada and continues in the San Francisco Bay Area in California. It grows on the western slopes of the Rocky Mountains in British Columbia, western Montana and isolated pockets in eastern Washington and northeastern Oregon (Cunningham 1994). The Pacific yew exists in dense forests, along streams, moist flats, slopes, deep ravines and coves at an elevation between 0-2200 meters (Elias 1980). The Pacific yew grows as an under-story dominant or co-dominant beneath a closed forest canopy in late-successional coniferous forests of the Pacific Northwest and northern Rocky Mountains. Over-story dominants include grand fir (Abies grandis), white fir (Abies concolor), and western hemlock (Tsuga heterophylla). Vine maple (Acer circinatum), queencup beadlily (Clintonia uniflora), and wild ginger (Asarum caudatum) are common co-dominants. These trees provide the necessary shade for the yew’s growth. Pacific yew is found in dry, sub humid rocky areas with an average annual precipitation as low as 470 mm, in this environment it is confined to streamside areas and the lower third of north-facing slopes. It is also found within humid forests with precipitation of 1400 to 4000 mm, in this soil rich environment it can be found on all slopes, benches, and ridge tops. In general the Pacific yew functions best in wetter forests of the coastal areas and the interior wet belt region. Pacific yews are best suited to grow in deep, moist, rich, rocky soils such as ultisols, alfisols, and inceptisols. In dry interior forests, the species develops best along mountain streams, and in shady canyons, ravines or coves (Elias 1980). Within the moist maritime climate of the Pacific Northwest, it grows most abundantly in drier, warmer environments.

Physical Characteristics
An evergreen tree growing to 15m at a slow rate. It is hardy to zone 6 and is frost tender. It is in leaf all year, in flower from March to May, and the seeds ripen from September to November. The flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required) and are pollinated by Wind. The plant not is self-fertile. We rate it 3 out of 5 for usefulness.
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils and requires well-drained soil. The plant prefers acid, neutral and basic (alkaline) soils and can grow in very acid and very alkaline soils. It can grow in full shade (deep woodland) semi-shade (light woodland) or no shade. It requires dry or moist soil. The plant can tolerates strong winds but not maritime exposure. It can tolerate atmospheric pollution.

Native Range
Pacific yew grows in forests from the southern tip of southeast Alaska- including Annette and Prince of Wales Island- south through the Pacific Coast region of British Columbia, Vancouver and the Queen Charlotte Islands, and the Olympic Peninsula of Washington. It is rare in the Coast Range south of the Olympic Peninsula in Washington and north of the Umpqua River in Oregon, but occurs with greater frequency in the Coast Range in southern Oregon and northern California. Isolated occurrences are found as far south as Marin and San Mateo Counties in California. Yew occurs in scattered localities in the valleys between the Coast Range and Cascade Ranges of Oregon and Washington. In the Cascade Range, it is fairly common at low to moderate elevations, and on some sites in southern Oregon it is abundant. Pacific yew extends south through the Klamath Mountains of California, then southeasterly to the western slopes of the Sierra Nevada. Its southern limit is in Calaveras County. Farther inland, it grows on the western slopes of the Rocky Mountains in British Columbia, south into northern Idaho and western Montana, the Lewis Range in Montana, and isolated areas in eastern Washington and northeastern Oregon. In the South Fork of the Clearwater River basin in Idaho, Pacific yew deviates from its role as a minor forest component and becomes a dominant on about 16 000 hectares (40,000 acres).

Pacific yew is found over a wide range of moisture and temperature conditions. In dry, subhumid areas with an average annual precipitation as low as 470 mm (19 in), it is confined to streamside areas and the lower third of north-facing slopes. Some large specimens can be found in such environments; for example, the largest known yew tree in Idaho- 84.8 cm (33.4 in) d.b.h. and 8.5 m (28 ft) tall- is at the bottom of Hell’s Canyon in an area that receives about 500 mm (20 in) of precipitation annually . On the Queen Charlotte Islands, Pacific yew is confined to the borders of inlets (44). Throughout much of its range within humid and superhumid forests (precipitation of 1400 to 4000 mm [55 to 157 in]), it can be found on all slopes, benches, and ridgetops. For example, a large yew tree in Oxbow County Park near Troutdale, Oregon (precipitation about 1450 mm [57 in]), is on the highest point in the park, a 210-m (690-ft) ridge overlooking the Sandy River 168 m (550 ft) below. Pacific yew is found from sea level in coastal areas to 2440 m (8,000 ft) in the Sierra Nevada. Length of growing season ranges from 60 to 300 days, with annual minimum temperatures from -15° to -12° C (5° to 10° F) .

Soils and Topography
Pacific yew grows best on deep, moist or rich, rocky or gravelly soils. In dry interior forests, the species develops best along mountain streams, and in shady canyons, ravines, and coves. Within the moist maritime climate of the Pacific Northwest, it grows most abundantly in drier, warmer environments. A partial list of soils on which Pacific yew grows includes those in the orders Ultisols, Alfisols, and Inceptisols.

Associated Forest Cover
Pacific yew commonly occurs as an understory species in several forest cover types. It is a major component in some stands, but in most it is minor to rare. In some types, it tends to be found mostly on microsites. Some examples: In stands of ponderosa pine (Pinus ponderosa), grand fir (Abies grandis), and western larch (Larix occidentalis) in the drier interior forests, yew is found in moist areas near streams and springs (but on well drained soil); on wet, hummocky sites west of the Cascades, yew can be found in Oregon white oak (Quercus garryana)-Oregon ash (Fraxinus latifolia) stands (ash occupies the low, wet spots and yew grows with the oak on slightly raised hummocks); scattered large yew trees grow along the Clackamas River in northwest Oregon on berms and banks between first and second bottomlands in stands of black cottonwood (Populus trichocarpa), red alder (Alnus rubra), hawthorn (Crataegus spp.), crab apple (Malus spp.), and willow (Salix spp.). By far, Pacific yew is most common in dense conifer forests. Among the major Society of American Foresters cover types in which Pacific yew is found are: Engelmann Spruce-Subalpine Fir, Interior Douglas-Fir, White Fir, Grand Fir, Black Cottonwood-Willow, Western Hemlock, Western Redcedar-Western Hemlock, Western Redcedar, Pacific Douglas-Fir, Douglas-Fir-Western Hemlock, Port-Orford-Cedar, Redwood, Oregon White Oak, Douglas-Fir-Tanoak-Pacific Madrone, Sierra Nevada Mixed Conifer , and Pacific Ponderosa Pine-Douglas-Fir.

Life History
Reproduction and Early Growth
Flowering and Fruiting- Pacific yew is dioecious. Male strobili are stalked, bud-like, pale yellow, and composed of 6 to 12 filamentous stamens, each with 5 to 9 anthers. They are abundant on the underside of branch sprays and usually appear in May or June. Female strobili are less abundant, greenish, and composed of several scales. They also are borne on the underside of branches. The fruit is an ovoid-oblong seed about 8 mm (0.3 in) long, partially enveloped by a fleshy, berrylike, scarlet, cup-shaped disk called an aril. Pollen is dispersed by wind in the spring.

Seed Production and Dissemination- Fruits ripen from August to October of the same year that flowering occurs. Fruits either drop to the ground or are taken from trees by birds or rodents. Birds devour the fleshy arils and void the seeds which remain viable. Chipmunks and squirrels often take only the seeds. Rodents and some birds-nuthatches, for example-cache yew seeds, thus creating the clusters of yew seedlings observed in some areas. The seed is about 6 mm (0.24 in) long with a depressed hilum, bony inner coat, and membranous outer seedcoat. Pacific yew is a prolific seeder. Seeds average about 33,100/kg (15,000/1b) after cleaning. The frequency of good seed crops is unknown.

Seedling Development- Seeds of Pacific yew germinate slowly and require stratification. Germination tests indicate that 30° C (86° F) day and 20° C (68° F) night temperatures are desirable. Germination is epigeal, and usually in heavy organic matter. In a study in Idaho, wild yew seedlings were distributed in seedbeds as follows:

Yew seeds sown in nursery beds in late spring require mulching. Beds require shading during the summer and again in December. Some seeds do not germinate until the second spring after sowing.

Vegetative Reproduction- Pacific yew is capable of layering and often sprouts from stumps or rootstocks after the top has been killed or the tree cut. Layering usually occurs after branches or tree tops have been pressed to the ground for a prolonged period by large fallen trees or limbs, although occasional old yew trees can be found surrounded by a ring of well rooted branches that were apparently held down only by their own weight and the weight of snow in the winter.

Although Pacific yew is sensitive to heat, sprouts that originated from the bases of burned stumps were reported from the Rogue River National Forest in southern Oregon. Young yew trees that originated by layering and sprouting were observed in a sunny, south-facing clearcut on the Mount Hood National Forest in northern Oregon. From one cut yew tree with a stump diameter of 30 cm (12 in), seven new trees had originated by layering before cutting, and a clump of vigorous stump sprouts had originated after cutting. Sprouts emerged from one side of the 36-cm-high (14 in) stump (the opposite side had been debarked during logging) from ground level to the top. The layers were 1.0 m to 2.5 m (3 ft to 8 ft) from the stump. Most of the layers had been damaged by logging and lacked the vigor of the stump sprouts.

Sapling and Pole Stages to Maturity
Growth and Yield- Pacific yew, unlike most woody plants that grow in heavily shaded forest understories, often has a straight bole. Although yew trees are reported to have typically fluted, ridged, and asymmetrical trunks, often with tightly spiraled grain, yew cutters in southwest Oregon reported that many yew trunks were round and unfluted above the base section, and straight-grained. Large limbs are common in the mid and upper bole. The crown tends to be ragged and lopsided. Pacific yew “reaches” for light by way of limbs that may be as long as the tree is tall. Young trees often have an umbrella-shaped crown of flat branches, and old trees have long drooping spray-like branches. Pacific yew is sometimes shrub-like, forming dense thickets. In western Montana, parts of Idaho, northeastern California, the Blue Mountains of eastern Oregon and southeastern Washington, and at high elevations throughout its range, the shrub form of yew often occurs in the absence of tree-size specimens. In other areas, large tree-size yews may occasionally be found in or near yew shrub thickets. Whether the differences in size and form are genetic traits or the results of environment and stand history is not known.

The needles of Pacific yew are dark green on the underside, two ranked, and spirally arranged on twigs. The bark is purplish, papery thin, and scalelike. New bark is rose red. The wood is fine grained, hard, and heavy: at 712 kg/m? (about 44 lb/ft?) (8 percent moisture content), it is the heaviest of U.S. conifers, comparable in weight to high-density hardwoods such as ash, oak, and hard maple. Heartwood is red to brownish red, and sapwood is whitish yellow to bright yellow.

Pacific yew grows slowly, taking about the same time to grow to 30 cm (12 in) in d.b.h. as other conifers in the same stand take to grow to several times that size. Height growth is correspondingly slow. Trees larger than 50 cm (20 in) in d.b.h. and taller than 12 m (40 ft) are rare within most of the species’ range: they account for less than 2 percent of the yew trees tallied on inventory plots on non-Federal land in California, Oregon, and Washington.

Because of the slow growth of individual trees and because the species is typically found as an occasional tree in stands of other tree species, volumes and yields of Pacific yew are low. Stands with 125 yew trees/ha (50/acre) that are 20 cm (8 in) in d.b.h. and larger have been observed, but always in association with other species. The theoretical volume of yew wood in such stands could be as much as 140 m?/ha (2,000 ft?/acre), including the volume in main stems from ground level to tip. The greatest volume of Pacific yew found in randomly located plots on non-Federal land in California, Oregon, and Washington was 28 m?/ha (400 ft?/acre). These are gross volume estimates. Because heart rot is prevalent in large yew trees, net volume would be considerably less.

The largest known Pacific yew tree is found in a cool, moist valley in western Washington (28). Large yew trees are, however, more prevalent on somewhat drier sites with warm, moist winters. Forty-seven percent of all the yew trees larger than 30 cm (12 in) tallied on inventory plots on non-Federal land in California, Oregon, and Washington were in a 4-county area in southwestern Oregon at mid to low elevations in the drier interior valleys and slopes between the Cascade and Coast Ranges, and in the Klamath Mountains .

Although Pacific yew is sometimes damaged by heat, frost, and wind, especially after overstory trees have been removed , it can sometimes respond to release. On permanent plots in western Oregon measured 12 years apart, diameters of undamaged yew trees left after removal of overstory trees grew an average of 0.18 cm/yr (0-07 in/yr) and trees under dense overstories grew 0.06 cm (0.02 in).

The adaptation of Pacific yew to overstory removal is made possible through morphological changes in the needles-length, cuticle thickness, and deflection from the horizontal-and development of epicormic twigs .

Rooting Habit– The root system of Pacific yew is deep and wide-spreading.

Reaction to Competition- Pacific yew is very tolerant of shade. It appears to require shade for establishment and can grow and develop under heavy forest canopies. On many sites, it is able to adapt to overstory removal, and large, old trees can be found that have been in the open much of their lives .

Damaging Agents– Pacific yew is sensitive to damage from fire, and, where the overstory has been removed, it is sometimes damaged by exposure to the sun, wind, and cold. It resists damage from sulfur dioxide and was the least sensitive of 12 coniferous species to smelter fumes at Trail, British Columbia. Diseases of Pacific yew seedlings have not been studied, but Rhizoctonia solani, Phytophthora cinnamoni, and Pythium sp. have caused damping-off and seedling root rot in yews in the East. No serious leaf diseases have been reported. Snow blights- Neopeckia coulteri and Herpotrichia juniperi- have caused localized damage, and four needle blights are caused by Macrophoma taxi, Mycosphaerella taxi, Phoma hystrella, and Sphaerulina taxi. A stem canker is caused by Diplodia taxi, and twig blights by P. hystrella and Physalopspora gregaria. Two root diseases- Armillaria ostoyae (obscura) and Phaeolus schweinitzii have been reported on Pacific yew in Idaho.

Although seasoned heartwood of Pacific yew is extremely durable, large living Pacific yew trees often have heartrot or hollow boles. Many of the yew trees over 50 cm (20 in) d.b.h. tallied on non-Federal land in California, Oregon, and Washington could not be bored to determine age because of rotten or hollow trunks. Heartrot fungi infecting Pacific yew include Phellinus nigrolimitatus, P. pini, P. robustus, and Fomitopsis rosea .

Several insects cause damage to yews in the eastern United States, including Lecanium fletcheri (called Fletcher scale or taxus lecanium), Pseudococcus comstocki (Comstock mealybug), Dysmicoccus wistariae, Pseudococcus maritimus (grape mealybug), and Maladera castanea (Asiatic garden beetle). No damage to Pacific yew in forested settings has been confirmed. Reported damage to Pacific yew foliage by budworms (Choristoneura spp.) in areas of heavy budworm infestation is thought to be heat or frost damage resulting from the defoliation of the overstory .

Special Uses
• Modern – taxol
• Traditional – bows, tools, paddles, snowshoe frames; the fruit, although considered toxic, was sometimes eaten in small amounts; inner bark: braiding, weaving

The wood of Pacific yew has been used for archery bows, canoe paddles, tool handles, gunstocks, boat decking, furniture, musical instruments, carved figurines, and miscellaneous novelty items. (In a recent western State gubernatorial election, campaign buttons were made of yew wood.) Japanese have used Pacific yew for ceremonial “Toko” poles, which they place next to entrances of their homes . Pacific yew’s resistance to decay makes it useful for fenceposts. Of seven northwest species tested for use as untreated fenceposts, Pacific yew was the second most durable, with an average service life of 25 years . In the mid-1980’s Japanese purchasers paid $3,600 per thousand board feet (Scribner scale) for Pacific yew logs, mostly for wood carvings. In 1989, Japanese buyers agreed to pay $4,150 per thousand for grade 1 yew logs, and a Taiwanese buyer paid $6,100 .

Among Native Americans, Saanich Tribal women used Pacific yew to remove underarm hair; Okanagans made a red paint from ground yew wood mixed with fish oil; several tribes smoked dried yew needles, which was said to cause dizziness; Haidas believed that women who ate yew berries would not conceive. Yew was valued as an item of trade and used in making instruments for hunting, fishing, and warring; tools, such as mauls and splitting wedges; household utensils, such as bowls and spoons; and medicine for a broad range of ailments .

Pacific yew is again being used for medicinal purposes. In the late 1960’s, taxol-a complex compound extracted from yew bark-was identified as a possible anticancer agent . The National Cancer Institute (NCI) has found taxol to be one of the most promising of more than 120,000 plant compounds tested for anticancer properties. Taxol appears to be effective against a wide range of tumors, and good responses have been obtained in the treatment of refractory ovarian cancer.

In 1988, the NCI acquired 27 700 kg (60,000 lb) of dried Pacific yew bark, collected from trees cut down in southwestern Oregon. On average, one yew tree yielded 18 kg (40 lb) of green bark, which weighed about 9 kg (19 lb) dried. From the 27 700 kg of dried bark, about 4 kg (9 lb) of dry, crystalline taxol was extracted. Clinicians in several locations across the country have asked for increased supplies of taxol to expand tests to a broader range of cancer types. In January 1989, the NCI solicited another 27 700 kg of yew bark.

The 27 700 kg of yew bark already collected and the second 27 700 kg ordered represent 6,000 to 7,000 trees. Most of these trees were cut or will be cut on Federal forest land where yew has not been inventoried. On non-Federal lands in California, Oregon, and Washington, where inventories have been made, there are an estimated 700,000 Pacific yew trees 28 cm (11 in) d.b.h. and larger, the size of most trees cut for bark collection. Almost all the yew trees on non-Federal land are survivors of logging operations that removed the old-growth overstory. On Federal land where old-growth forests still exist, many more yew trees are thought to be present, but trees of the size needed to produce large quantities of bark are not abundant in most areas. An unknown but unquestionably significant percentage of the original yew resource has already been destroyed in logging. In the process of harvesting Douglas-fir and other timber species, mostly by clearcutting, yew trees were either cut or knocked over and broken up by machinery. Yew trees were seldom taken in primary logging operations, but some yew wood was later salvaged by firewood cutters and gleaners gathering wood for specialty products. Most of the yew trees that existed in logged areas were burned in slash-disposal fires. In many logged areas, the rootstocks have survived and resprouted, so, although the wood and bark of many yew trees were destroyed, there seems to have been little threat to the existence of the yew germ plasm.

Continued or increased demand for yew bark for taxol production could further decrease a resource that has already been greatly reduced. Attempts to synthesize taxol in the laboratory have failed, and prospects for success in the future are considered to be poor. The only known source of taxol now is yew bark. Taxol has been found in most of the several other species of Taxus that exist, but Pacific yew is the only one that is considered to be a practical source of quantities sufficient for clinical use. At least one private organization has begun to investigate alternative ways of producing taxol, through tissue culture and by growing vegetatively propagated seedlings in a controlled environment.

The several species of yew in both the western and eastern hemispheres are thought to have poisonous seeds and foliage. Incidents of livestock poisoning by yew have been reported in Europe and North America. Conversely, in both Europe and North America, domestic and wild animals are known to browse yew foliage without ill effects. If and under what conditions yew foliage is poisonous are not known. Pacific yew is browsed by moose in the South Fork of the Clearwater River basin in Idaho, where the tree is considered critical to the animals’ survival. Pacific yew is also browsed heavily by elk and occasionally by deer in Oregon and Washington.

Sprouts and epicormic branches that form in response to stand disturbance are favored by browsing animals. Repeatedly browsed yews in clearcut areas sometimes develop compact bushy crowns resembling the yew topiary of English gardens. Some limited use of T. brevifolia as an ornamental indicates it also has potential as a shade tree, for hedges, and for topiary.

Pacific yew occurs in nature as a shrub or a tree, but whether the two forms are distinct subspecies, races, or varieties is not known. Three cultivars have been reported: cv erecta, a columnar form; cv nana, a dwarf form; and cv nutallii, a drooping form. A hybrid between Taxus brevifolia and T. cuspidata (Japanese yew) has been reported, but has no botanical standing. Pacific yew was originally classified as a variety of T. baccata (European yew), which it closely resembles; some botanists grouped all seven of the currently recognized species of Taxus worldwide as varieties of T. baccata. Where different species grow near each other, interspecific hybrids frequently occur, lending support to the view that there is but one species . Further evidence of the close similarity of the species of Taxus is provided by bark analyses which show that most species contain taxol , and by an analysis of heartwood constituents of T. baccata, T. brevifolia, T. cuspidata, and T. floridana: the four species were found to be “chemically almost indistinguishable”

Edible Uses
Fruit – raw Very sweet and gelatinous, most people find it delicious though some find it sickly[K]. The fruit is a fleshy berry about 8mm in diameter and containing a single seed. Trees usually produce good crops every year. All other parts of this plant, including the seed, are highly poisonous. When eating the fruit you should spit out the large seed found in the fruit’s centre. Should you swallow the whole seed it will just pass straight through you without harm, if the seed has been bitten into, however, it could cause some problems.

Other Uses
Paint; Wood.
A red paint was made by mixing the woodchips with oil.

The roots have been used as the weft in twined basketry. The root is very strong and is particularly good for hopper mortar baskets.

Wood – fine-grained, strong, hard, heavy, durable and resilient, taking a very fine polish. Though hard, the wood is easy to carve[226]. It is also used for making paddles, fence posts and various other small articles.

Cultivation details
Thrives in almost any soil, acid or alkaline, as long as it is well-drained. Succeeds in dry soils. Plants are very shade tolerant.

Dormant plants are very cold-hardy, though the young growth in spring can be damaged by late frosts.

A slow-growing but apparently long-lived tree.

Plants produce very little fibrous root and should be planted in their final positions when still small.

Plants in this genus are notably resistant to honey fungus.

Dioecious. Male and female plants must be grown if seed is required.

Seed – can be very slow to germinate, often taking 2 or more years. It is best sown as soon as it is ripe in the autumn when it should germinate 18 months later. Stored seed may take 2 years or more to germinate. 4 months warm followed by 4 months cold stratification may help reduce the germination time. Harvesting the seed ‘green’ (when fully developed but before it has dried on the plant) and then sowing it immediately has not been found to reduce the germination time because the inhibiting factors develop too early. Prick out the seedlings into individual pots once they are large enough to handle and grow them on in pots in a cold frame. The seedlings are very slow-growing and will probably require at least 2 years of pot cultivation before being large enough to plant out. Any planting out is best done in late spring or early summer, after the last expected frosts[K].

Cuttings of half-ripe terminal shoots, 5 – 8cm long, July/August in a shaded frame. Should root by late September but leave them in the frame over winter and plant out in late spring. High percentage.

Cuttings of ripe terminal shoots, taken in winter after a hard frost, in a shaded frame.