The moon is perhaps humankind’s oldest form of marking time. According to some scholars, the Celts used a Lunar Calendar that consisted of 13 months, each 28 days in length. Each month of the Celtic Lunar calendar bears the name of a tree, which also stands for one of the consonants in the Celtic ‘tree alphabet’. There are basically two different versions of this Lunar calendar: the Beth-Luis-Nion (which begins on the Winter Solstice) and the Beth-Luis-Fearn (which begins on Samhain). I work with the Beth-Luis-Nion simply because it seems to work the best for my style of Witchcraft.

Beth-Luis-Nion version of The Celtic Tree calendar

  • B – Beth, the Birch Month (December 24th – January 20th)
  • L – Luis, the Rowan Month (January 21st – February 17th)
  • N – Nion, the Ash month (February 18th – March 17th)
  • F – Fearn, the Alder Month (March 18th – April 14th)
  • S – Saille, the Willow Month (April 15th – May 12th)
  • H – Huath, the Hawthorn Month (May 13th – June 9th)
  • D – Duir, the Oak Month (Jun 10th – July 7th)
  • T – Tinne, the Holly Month (July 8th – August 4th)
  • C – Coll, the Hazel Month (August 5th – September 1st)
  • M – Muin, the Vine Month (September 2nd – September 29th)
  • G – Gort, the Ivy Month (September 30th – October 27th
  • Ng – Ngetal, the Reed Month (October 28th – November 24th)
  • R – Ruis, the Elder Month (November 25th – December 23rd)

The five vowels I, A, O, U, and E have corresponding tree names to the nights of the solstices and equinoxes:

  • I – Idho, the Night of the Yew, Winter Solstice Eve
  • A – Ailm, the Night of the Silver Fir, Winter Solstice
  • * – Herb too sacred to have a Celtic name, the Night of Mistletoe, Day after Winter Solstice
  • O – Onn, the Night of the Gorse Bush, Spring Equinox
  • U – Ura, the Night of the Heather, Summer Solstice
  • E – Eadha, the Night of the White Poplar, Alban Elfed or Autumnal Equinox


  • Birch, 1st Moon of the Celtic Year – (Dec 24 – Jan 21)
  • Rowan, 2nd Moon of the Celtic Year – (Jan 22 – Feb 18)
  • Ash, 3rd Moon of the Celtic Year – (Feb 18 – March 17)
  • Alder, 4th Moon of the Celtic Year – (March 18 – April 14)
  • Willow, 5th Moon of the Celtic Year – (April 15 – May 12)
  • Hawthorn, 6th Moon of the Celtic Year – (May 13 – June 9)
  • Oak, 7th Moon of the Celtic Year – (June 10 – July 7)
  • Holly, 8th Moon of the Celtic Year – (July 8 – Aug 4)
  • Hazel, 9th Moon of the Celtic Year – (Aug 5 – Sept 1)
  • Vine, 10th Moon of the Celtic Year – (Sept 2 – Sept 29)
  • Ivy, 11th Moon of the Celtic Year – (Sept 30 – Oct 27)
  • Reed, 12th Moon of the Celtic Year – (Oct 28 – Nov 24)
  • Elder, 13th Moon of the Celtic Year – (Nov 25 – Dec 23)
  • Furze, Tree of the Spring Equinox (Aprox. March 20)
  • Heather, Tree of the Summer Solstice (Aprox. June 20)
  • Poplar, Tree of the Fall Equinox – (Aprox. September 22)
  • Yew, Tree of the day before the Winter Solstice (Aprox. December 21)
  • Fir, Tree of the day of the Winter Solstice
  • Mistletoe, Tree of the day after the Winter Solstice (Aprox. December 23)


  • Year of Moons, Season of Trees by Pattalee Glass-Koentop
  • Tree Medicine Tree Magic by Ellen Evert Hopman
  • A Druid’s Herbal by Ellen Evert Hopman
  • Celtic Astrology by Helena Paterson
  • Glamoury – Magic of the Celtic Green World by Steve Blamires
  • The Book of Druidry by Ross Nichols

Document Copyright 1999-2006 by Sarah Nunn (Sarah the SwampWitch). This document can be re-published and shared only as long as no information is lost or changed, credit is given to the author, and it is provided or used without cost to others. Other uses of this document must be approved in writing by Sarah Nunn.