The Moon is humanity's oldest calendar. Evidence of ancient peoples keeping time by the phases of the moon have been found carved into rocks and cave walls the world over. The famous tree calendar of the Celts was such a time-keeping device, and, like other tribal cultures, the Celts found names and associations for their moon which were developed and codified over many years of ritual and experimentation. Each moon phase was assigned a corresponding tree, each tree being sacred to either feminine energy and to the Goddess, or to masculine energy and to the God.
The lunar tree calendar of the Celts has long been a source of controversy amont Celtic scholars. Some even claim it was never a part of the old Celtic world, but was an invention of author/researcher Robert Graves. The Druids are generally given credit by other researchers for creating this system. There seems to be no scholarly evidence to prove otherwise, yet many Celtic Pagans feel that the system pre-dates the time of Druidic influence over Celtic religious matters. It is probably reasonable to believe that the truth lies somewhere in between these three extremes. It is most likely that the tree system was in place, with minor regional variations before the time of the Druids who experimented with it, discovered the magickal properties of each tree, and codified all the information into the system we have today.
The trees the Druids selected for the thirteen months were already trees which were sources of magick and myth in Celtic folklore. Several of the trees are said to be attractive to faery folk, and others were sources of magick herbs or medicines.
Today the counting of the Celtic tree calendar begins with the full moon nearest Yule. Perhaps it once began with the full moon nearest Samhain since, until the influence of the Norse, Samhain marked the beginning of the Celtic New Year. When you have pinpointed the full moon closest to Yule, count off the thirteen moons of the lunar year and mark them with their Tree Calendar names.*
