The genus of Taxus contains eight species of Yew tree and the two most commonly used for bonsai are Taxus baccata (English Yew) and Taxus cuspidata (Japanese Yew).

Yews are:-

  • Evergreen
  • Conifers
  • Slow growing
  • Long lived
  • Have red berries that are poisonous
  • Are dioecious
  • Have needles for leaves that are poisonous containing the alkaloid taxane
  • Have a red bark that flakes and a trunk that flutes and forms ridges as it ages
  • Has chemical properties within its leaves that aid with new drug treatments for certain forms of cancer

English Yew

This species has historical associations dating back to medieval times and the wood was an essential resource in the creation of the long bows that were used as weapons as well as spears prior to this. The reason for this is that yew wood is very flexible and also fairly water resistant and thus easily shaped for form a bow. English yew are commonly found in Church Yards and cemeteries and in woodlands as understory trees, as they tend to be quite short trees only reaching up to 10-15 meters in height.

Yew as a bonsai

They make excellent bonsai as they are easy to carve, have all year round interest with the dark green foliage and respond well to pruning. They are easy to develop foliage pads with, and back bud profusely on old and new wood and back on the main trunk so new branches are always readily available. However, they are slow growing, they are not frost tolerant as they have large fleshy roots that are vulnerable to frost damage when kept in bonsai pots.

Bonsai styles

They make the majority of bonsai styles with the exception of the broom style and are more often seen as larger bonsai as opposed to shohin or mame but would look good at any size. It is often acceptable to also have gins and sharis on Yew trees to accentuate the trunk line and also improve the impression of age and maturity but try to ensure that these are blended into the overall style of the tree and do not stand out independently from the tree. Another key feature often seen on Yew as bonsai is the hollow trunk as this is very characteristic of again mature Yew trees in nature as the hollowing of the trunks is part of the natural ageing process.

Positioning

They are flexible with regard to position and will tolerate full sun or partial shade. In partial shade the foliage tends to be darker green, and they will also cope in full shade. As a species they are used to growing underneath the canopies of larger deciduous trees in woodlands so preference would be for dappled light levels in summer and full light levels in winter to mimic nature. However, a note of caution, if your yew is used to growing in low light levels then do not expose it to high light levels during hot periods as they take years to acclimatize to the change in light levels and their vitality may suffer in the process.

Feeding

With any bonsai, feeding is an essential part of maintain healthy trees and subject to the state of development of your bonsai as to how much feed you give them. If you are wanting to encourage masses of new growth then feed more heavily however it is still important to feed trees that are developed to ensure they remain healthy. They can also be fed all year round due to being evergreen but reduce the quantity of food during the more dormant period over the winter months. To ensure your yew is healthy focus the feeding with potassium, phosphorus and calcium, and maintain a alkaline pH in the soil.

Watering

Yew trees have fleshy roots so do not like to dry out totally but also are prone to root rot if they sit in water. So ensure that their soil medium is kept moist at all times, but not wet, and reduce the watering down over the winter period.

English Yew in training as a Bonsai

Pruning

New growth can be cut with sharp pruning scissors or pinched by hand to encourage back budding. Thinning out of the foliage along the branches will also promote back budding at the same time as this allows for light to the branches which stimulates new buds to flush.

Subject to whether you have a male or female yew as they are dioecious (tree species which bear male and female flowers on separate plants) you may not get fruit if you have a male tree as they bear the pollen while the females bear the red fruits. However, fruiting does not occur on younger trees and it can take many years for a female yew tree to bear either flowers or fruit. Also to note, that the seed of the yew tree is highly toxic while the red fleshy part, the aril is non-toxic.

If your Yew bonsai is female and does fruit, to ensure that you get fruit, do not trim the new shoots until after the small green flowers have appeared in spring. Yew trees come of age around 30-35 years of age for fruiting but this can be delayed until 70-120 years in some cases.

Female Yew tree

Female Yew tree with red fruits

Male Yew tree with pollen cones

Structure pruning should be done during the autumn and winter months prior to spring and wiring also is preferable during this time but actually can be done at any time.

Furthermore, be aware that the needles on yew differ dependent on the exposure to light levels and due to pruning for bonsai, often the outer thicker needles that are more suited to dealing with higher light levels and associated water loss will be removed so this should be considered with regard to positioning of your yew tree post pruning in a more shady area.

Growth rates

Yew are known as slow growing trees but will produce a good quantity of growth while they are juvenile which is a state they remain in for a considerable period of time due to their longevity. Thus as a bonsai the Yew does actually grow well particularly if fed well alongside the good amount of adventitious buds that form too. However, as yew trees age, they can become dormant for extended periods of time, and may only grow in girth and not height or not at all. This usually only affects trees in excess of a few hundred years of age.

 

Propagation

The best form of propagation is from cuttings from the current season’s growth that are taken in autumn and protected over winter. Another method is via air layering in summer and this is very successful, along with the formation of rafts from lying a tree down in soil and letting the side shoots grow vertically to form a row of trees along the trunk. Another good way is to collect seedlings from the woods, as they freely regenerate naturally if you find a mature stand of yew trees.

Bonsai pot

Subject to the age of the bonsai and style, the colour of the pot will vary, however a traditional colour used is that of a dark brown unglazed pot as this accentuates the foliage colour, grounds the tree well and also compliments the red / brown bark. The pot shapes tend to be oval or rectangular and slate is sometimes used.

Re-potting

The soil mix for Yews is dependent on the maturity of your tree as a bonsai, but in general terms it should be an open free draining mix that allows the roots sufficient air spaces between the particles to thrive and not be waterlogged. It should also be a mix that does not remain cold during the winter that offers the fleshy roots a level of protection within the pot.

Pests and diseases

Yews as bonsai are prone to scale insect, mites including red spider mite as well as certain galls like the artichoke gall that forms on the buds. Remove the galls if they form and treat for scale by picking them off when present and treat accordingly with a systemic pesticide if scale persists. However, pests only seem to become a problem when the trees are less healthy, so try to maintain good health levels and also allow for space between the bonsai trees in your collection to reduce pest cross infection.

Sources of information:

Websites of interest: –

Ancient Yew group – http://www.ancient-yew.org/mi.php/the-yew-wood/103

Books: –

  • Addison, J & Hillhouse, C (1999) Treasury of tree lore, (Past Times, Jarrold Boom printing)
  • Bartholomew, J (1996) Yew & Non Yew Gardening for horticultural climbers (Arrow)
  • Baton, D (1989) The Bonsai Book (Ebury Press)
  • Baxter, T (1992) The external Yew (The self publishing association ltd)
  • Bevan-Jones, R (2002) The Ancient Yew (Windgather press)
  • Bitner, R (2007) Conifers for Gardens, (Timber press)
  • Hadeneder, F (2011) Yew A History (The History Press)
  • Hillier, J & Coombes, A (2007) The Hillier Manual of Trees and shrubs (David & Charles Ltd)
  • Hopman, EE (1991) Tree medicine and tree magic (Phoenix)
  • Tomlinson, H (1990) The complete book of bonsai (Dorling Kindersley, London)