Sandys Nursery Online Thuja Green Giant Arborvitae ~Fast Growing Trees~ Gallon The fastest growing tree Sandys Nursery Online offers. Privacy Screen-Height: 30-50 feet & Width: 12-16 feet Growth Habit: Pyramidal evergreen tree. Foliage: Medium to dark green. Hardiness Zone: 5-8 Ships: (1) trade Gallon Pot with soil and staked off for shipping.