Fairy tree in Tara Hill, Ireland. Trees hold significance importance in the Celtic way of life. Many have healing powers and are considered home to varied spirits such as fairies. Hawthorn trees are also called Wishing trees, May Bushes, or Rag Trees. People tie ribbons to ask for blessings from the local saints or spirits. The Hawthorn tree flowers in May during the time of Beltaine. Often you'll find these trees beside a holy well, or equally it could note the site of an old well.