Thuja Green Giant (standishii x plicata 'Green Giant') is a large, fast-growing conifer that sports dense, dark green foliage. It takes on a pyramid shape via its flat splays and stays green throughout the year. "Thuja 'Green Giant' can quickly provide a lush, dense privacy screen that looks great all year round," says Walz. "It requires little or no pruning but can easily be sheared if necessary."