The Birch tree, being one of the first to come into leaf after the winter season, represents renewal and rebirth.

According to some sources, the mythological figure associated with this month is Taliesin.
His mother was the ancient lunar goddess Ceridwen, who got pregnant by trickery, and therefore put her baby son in a coracle, at the mercy of the sea. Fortunately, he was found and grew up to be Wales' greatest bard.

The animal associated with this month is the white stag, which figures in a lot of Celtic myths, where it is often a messenger of the Otherworld. Following a white stag can bring you unexpectedly in the presence of supernatural beings, so beware...
Furthermore, antlers have been found at various sanctuaries, and the horned deity Cernunnos was (is?) an important nature spirit.

The Ogham sign attributed to this month is Beth.