Based on the ’Celtic Tree Calendar’, as devised by Robert Graves in his book ‘The White Goddess’, there are 13 months to loosely correspond with the ancient Celtic lunar calendar.
BIRCH ~ Dec 24th – Jan 20th
ROWAN ~ Jan 21st – Feb 17th
ASH ~ Feb 18th – Mar 17th
ALDER ~ Mar 18th – Apr 14th
WILLOW ~ Apr 15th – May 12th
HAWTHORN ~ May 13th – Jun 9th
OAK ~ Jun 10th – Jul 7th
HOLLY ~ Jul 8th – Aug 4th
HAZEL ~ Aug 5th – Sep 1st
VINE ~ Sep 2nd – Sep 29th
IVY ~ Sep 30th – Oct 27th
BROOM ~ Oct 28th – Nov 24th
ELDER ~ Nov 25th – Dec 22nd
PINE/FIR ~ Dec 23rd**
(**According to Grave’s calendar – Dec 23rd is not ruled by any tree for it is the traditional day of the proverbial “Year and a Day” in the earliest courts of law. I have chosen to attribute Ailm (Pine/Fir) as this was the correspondence I learned for Yule in my Ogham studies.
Divine Ogham 