Touching a fairy tree is generally considered acceptable as long as you do so respectfully and without causing harm to the tree or its surroundings. In folklore and some cultural traditions, it is believed that certain trees, often old or distinctive ones, are inhabited or protected by fairies or other supernatural beings. People may leave offerings or tokens of respect at these trees. However, always be mindful of the environment and follow any local regulations or guidelines when interacting with trees or natural landmarks.