Learning Celtic Tree Astrology

Where it comes from

Start with the alphabet, because that part is solid.

The Ogham is an old Irish script. Its letters are groups of notches and strokes cut along the edge of a stone or a stick, and you can still see them on standing stones in Ireland and in the western parts of Britain, the earliest from about the fourth century. The medieval Irish scholars who wrote about the Ogham recorded names for its letters, and many of those names are trees: Beith for the birch, Duir for the oak, Coll for the hazel, Saille for the willow. Tree names on a real alphabet, carved by real people, a very long time ago. That much is on the record.

Now the calendar. The idea that those letters belong to thirteen months of the year, each ruled by its tree, is not ancient. It was set out in 1948 by the poet Robert Graves in his book The White Goddess, a long and strange work of poetic argument that few historians would call history. He took the tree letters and arranged them around a year of thirteen months, and the picture was so appealing that later writers picked it up, filled in the characters, and sold it as the astrology of the druids. There is no evidence the ancient Celts or their druids kept anything like it. Scholars of the Ogham have said so for decades.

I tell you this on the first page because I would rather you heard it from me than from someone trying to score a point. A tradition can be young and still useful, so long as it is described truthfully.

What it is and what it is not

What it is: thirteen character pictures, each drawn from a living tree, hung on the year in four week stretches. Each picture has a shape to it. The Birch starts things and clears the ground. The Rowan watches over. The Ash connects. The Alder holds the line. The Willow heals. The Hawthorn charms and defends. The Oak carries the weight. The Holly fights for a principle. The Hazel gathers and teaches. The Vine celebrates. The Ivy climbs and will not let go. The Reed speaks the truth out loud. The Elder sits with endings.

What it is not: a map of the sky. Nothing moves in it. There are no planets, no houses, no transits, no birth time, and nothing that changes from one year to the next. The thirteen months are called lunar months because thirteen stretches of about twenty eight days fill a year, and that is the whole of the lunar connection. They do not follow the Moon's phases. If you want the Moon, The Moon page in the Western Astrology section has it.

It is also not fortune telling. A tree describes a kind of person and the weather that kind of person tends to make. It never tells you what will happen on Tuesday.

How I read it

I read your tree as the tree you were planted under.

That is the image I hold, and I would ask you to hold it too. A seed does not choose its ground. It lands where it lands, and it grows the way its kind grows, and the ground it landed in shapes how that goes. A Birch planted in thin soil on cleared ground does what Birches do and gets on with it. A Willow by the water does what Willows do and leans toward what feeds it. Neither one is better. Neither one chose.

So when I say you are an Ash, I am holding up a picture of a tall tree with deep roots that lives on boundaries and ties things together, and I would like you to stand next to it for a minute and see how much of it is you. The stars did nothing to you on 14 March.

The image comes before the rule. Every tree page in this section starts with the living tree for that reason. Read the tree first and the person second, and the person will make more sense.

Beside the other systems

Your tree is one layer in a full portrait, and I never read it alone.

Each tree month overlaps parts of two Western signs, so your tree and your Sun sign will have something to say to each other. An Oak born in late June is an Oak and a Cancer, and the two pictures agree more often than you would expect: the steady presence and the one who brings everyone home. Your tree page names the overlap in a sentence and points you to The Signs. Then there is your Chinese animal, your Vedic Moon sign and your Mayan day sign, each in its own section under Astrology, and your numbers, which sit under Numerology. Thirteen systems make a portrait. One makes a snapshot.

The Celtic layer tends to be the one that gives people a picture they can carry around. Nobody forgets that they are a Hawthorn.

How this section is laid out

You are on the Learning page, the place to begin.

The Ogham and the Tree Calendar explains the alphabet in plain words, lists the thirteen letters this calendar uses with their trees and their dates, and sorts out what to do if your birthday sits on a boundary.

The Trees is the index of the thirteen, each with a line and its dates, and from there each tree has its own page: the living tree, who you are, strengths, challenges, love and work, the Ogham letter, and how it sits across the traditions.

Where to start

Find your tree. The dates are on The Ogham and the Tree Calendar page and on The Trees index, and they are fixed every year, so there is no sum to do. Sarah, born on 14 March, is an Ash. Emma, born on 6 August, is a Hazel. You will be as quick.

Read your own page first, slowly, and notice which lines you want to argue with. Then read a tree for someone you love. In my experience that second reading teaches more than the first.

You will be your own teacher. All I will do is help you remember what you already know.

If you would like your own chart read, my readings are here.