The Hebrew letter associated with the month of Shevat is the tzaddik, which itself has the form of a tree, with its spreading crown and established roots.
The letter tzaddik is, of course, representative of the actual tzaddik–the individual who has fulfilled his human potential, who is connected on high and down below, and whose nature is suffused with tzedek, or righteousness. Such a person is the perfect parallel of the month of Shevat, the month of the water bearer, because the tzaddik is entirely devoted to sharing the waters of G-d’s Torah with the world so that it can flourish like a healthy garden of trees that bear fruit.
Rebbe Nachman devoted so much of his teaching to the concept of the tzaddik–how important it is for us to be connected with real tzaddikim, how beneficial it is for us to learn from them. A great Jewish mystic once described the function of the tzaddik by way of a parable:
When a person enters a labyrinth–a garden maze whose walls are formed of tall shrubbery–he can spend so much time wandering around, getting stuck in dead ends and chasing his own trail, because he is down at ground level, working his way through. Such labyrinths are designed to have their end or solution at their very center, where there is a small garden, perhaps a fountain, where one can sit and rest and enjoy its peace. Now imagine a person who has already invested time and energy in solving this maze through trial and error, but instead of sitting down to rest he stands up on a column at the center, looking out for others who are wandering through. He is above the level of the walls, and waits to direct any other confused souls who are stuck in its pathways. From that height, he can see the entire maze laid out before him, and can point out to the seeker which turns to take to also reach the peaceful center.
Life is that labyrinth, and the person standing on the column is the tzaddik. Unless we pick up our heads and look to him for direction, we keep on hitting walls on our search for the solution.