Did you know that the trees once had their own language? Ogham (pronounced ‘OH-am’) is a set of angular letters representing twenty trees. Also known as the Celtic Tree Alphabet or Celtic Runes, it was in use from the fourth to the seventh centuries CE; today, it is still used in divination – the letter-symbols are carved onto pieces of wood and cast on a cloth for interpretation. 

According to Irish and Scottish mythology, the Ogham was invented by Ogma, the Irish god of poetry and written language. It is said that the Ogham alphabet begins with Beith (birch) because it was the first letter written by Ogma himself. I’ve written about Ogham in my 2021 book Nature’s Hidden Oracles, but just recently delved back into the lunar months associated with each tree. The source for the dates is The White Goddess, the seminal work on poetry and mythology by the English scholar Robert Graves.

The Ogham Calendar

Thirteen of 20 original Ogham letters are aligned with a 28-day lunar month and, just like zodiac signs, you can look up your Ogham sign to discover the tree associated with your date of birth. You may find you’re naturally drawn to your birth tree; my friend Chris has Huath, or hawthorn, as his birth tree. He is an artist and certainly a ‘visionary’ – and loves the wild hawthorn that grows in his back garden. Of course, there are many interpretations for the tree signs – what you have below is my take. You’ll find lots more online.

Tree                              Letters  Dates                                                    Qualities

Beith (Birch)                  B, P       December 24 to January 20                    The Achiever

Luis (Rowan)                  L           January 21 to February 17                      The Protector

Nion (Ash)                     N          February 18 to March 17                      The Healer

Fearn (Alder)                  F           March 18 to April 14                              The Empath

Saille (Willow)               S           April 15 to May 12                                 The Communicator

Huath (Hawthorn)          H          May 13 to June 9                                  The Visionary

Duir (Oak)                     D          June 10 to July 7                                    The Wisdom-Keeper

Tinne (Holly)                  T          July 8 to August 4                                  The Ruler

Coll (Hazel)                   C          August 5 to September 1                        The Truth-Teller

Muin (Vine)                   M         September 2 to September 29                 The Provider

Gort (Ivy)                       G         September 30 to October 27                  The Survivor

Ngetal (Reed)                 NG      October 28 to November 24                  The Harmoniser

Ruis (Elder)                    R          November 25 to December 22                The Change-Maker

December 23 does not have a Tree ruler. When dividing 365 days into the 28-day lunar calendar, one day is left over and can’t be officially added to another month, or that month would have 29 rather than 28 days. If your birthday falls on December 23, choose either Birch or Elder as your sign – see which you resonate with the most. 

Illustration: Ogham. From the Book of Ballymote, 14th century