How is the rowan tree used in rituals?

There is no specific reference to rituals using Rowan trees however, my research has found the following information about the tree.

The Mountain Ash or Rowan tree is ruled by the planet- the sun; is represented by the colour green; it governs spiritual strength and creative inspiration; as well it is sacred to the Celtic goddess, Brigid, and the English goddess Brigantia, (both of whom are aspects of the White Goddess) and is a symbol of the hidden mysteries of nature.

The Celtic month of the Rowan runs from January 21st to February 17th.

The wood is used in spells for protection, insight and cleansing. Two twigs of Rowan tied in an equal armed cross with a red ribbon are carried at Samhain as protection from the dead. The ripe berries are used as a tonic and a treatment for scurvy (due to high vitamin C content).

The trees are commonly planted along roadsides and near stone circles as they are thought to protect earth energies in the ley lines and standing stones. Boughs of Rowan are still hung over stables and dairies in remote farm areas, to protect the stock from barrenness and harm.

Rowan was planted in graveyards, to protect the spirits of the dead, and in gardens and sacred places as general blessing and protection.