
Duir or Oak
The Old King
Best known for its strong wood and great age, oaks usually live for six to eight hundred years (sometimes over 1,000). Less well-known is that more than five hundred species of insects depend on it for food and shelter, and a large number of birds and animals. It is well named as king of the forest! Squirrels and jays bury acorns as larders (which are then often forgotten), so regeneration of oaks is not under threat!

The lightning tree
Curiously, oak is sensitive to hard frost, which is why it is one of the last trees to produce leaves in spring. Its bark protects it from heat, and can help it survive forest fires, but lightning strikes the oak more often than most trees. Oaks like to grow above underground watercourses and possess strong electrical currents, far higher than that of any other tree.
Massive feet
The root system of the pedunculate oak is gigantic. While its overall shape is often wider than it is high (except in dense plantations), it can grow very irregularly in shape, with single branches spreading far out. In fact sudden changes of branch direction and an irregular crown are typical features of the oak, and its overall canopy, like its lobed leaves, are distinctively irregular.
The Planet effect
Just as the tides are the effects of the moon, all plants are affected by planets. Most trees do not show these effects, but oak does, and particularly Mars. The irregular growth of oak is not accidental since, every time Mars is behind the sun its distance away from Earth is seven times greater than it is a year later, when Earth and Mars are both on the same side of the Sun. Mars stimulates root growth and, when the planet spins off again, the sun stimulates upward growth.

Clothes and shoes
Oak has very high levels of tannic acid, which makes it excellent for tanning leather, so that immersing oak and leather in large tubs of water has been practised since Neolithic times. It is also antiseptic, with sterilising properties, and its bark or leaves have similarly been made into a tea as cure for bleeding, diarrhoea and used for gargles, washes and baths for treating rashes and wounds. In hard times, acorns were used as food, although they are very bitter.
Extra facts
Oaks are usually 70-80 years old before they produce acorns, and after a hundred years old they grow ony an inch each year. Oak wood is used for boat-building, barrels, beams and many uses in building, fencing, mining, garden furniture, sawdust as well as smoking herrings. Bark produces red and brown dyes, while the galls give a black dye, it is also used medicinally for treating malaria, dysentry, bleeding gums, sore throat, haemorrhage, and boiled it gives tonic for harness sores. Twigs make toothbrushes, galls make ink and acorns make wine. Oak belongs to the beech family: fagaceae pedunculate oak (quercus robar) sessile oak (quercus petraea)
The door tree
The word Duir (oak) means ‘door’, as does druid. A druid is therefore a ‘doorman’ or guardian of the (oak) door. It is a door that looks both ways - and Duir/oak ends the first half of celtic year at midsummer solstice. A similar figure in Roman times is Janus, who is usually illustrated with two heads that look either way.

Other Celtic gods
Thor and Lugh (the ‘Shining One’) are oak gods and guardians and are entitled to thunder (or use the lightning bolt) and in the Welsh poem Battle of the Trees Oak’s connection as door between worlds is made:
Before him tremble heaven and earth,
stout doorkeeper against the foe,
is his name in all lands.
The sacred oak at Dodona (Greece) was a major oracle of the Old World, and an international place of pilgrimage for nearly a thousand years. Its messages were interpreted from the rustling of its branches, from the murmur of the sacred spring that welled from beneath its roots, and through selection of one of the many oracle lots kept in an urn beneath it.
Added notes
In Egypt oak has origins in Amon Ra (the ram) an eight-rayed sun-disc in hand and spiral of immortality sprouting from his head; mistletoe grows on oak, and so lives “between heaven & earth”.
Additional bits
Calendar: May 24—Jun 20 (hence 21st is ‘and a day’ or ‘day out of time’)
Ogham: kingship; first digit of index finger, Thursday (Thor’s day), Jupiter; two vertical upward strokes; centre of lintel, forms beginning and end of year with tinne/holly; droen(druien) (wren); dubh (black); white carnelian (glaring hot); number: 12