Leyland Cypress is a very fast grower. One to two feet a year. But you didn't say what kind of tree. Deciduous (loses it's leaves) or evergreen (stays green all year long)
Leyland cypress is light-demanding but is tolerant of high levels of pollution and salt spray. A hardy, fast-growing natural hybrid, it thrives on a variety of soils and sites are commonly planted in gardens to provide a quick boundary or shelter hedge, because of their rapid growth. Although widely used for screening, it has not been planted much for forestry purposes. In both forms of the hybrid, Leyland cypress combines the hardiness of the Nootka or Alaska cypress with the fast growth of the Monterey cypress