Culture
Best grown in moist, fertile, well-drained soils in full sun to part shade. Tolerates somewhat wide range of soils and some dry conditions. Best in full sun, but generally appreciates some light afternoon shade in hot summer climates such as the St. Louis area. For screens, plant trees 5-6’ apart. Plant trees further apart for other uses.
Noteworthy Characteristics
Thuja is a genus of 6 species of coniferous, evergreen trees from East Asia and North America. Sizes range from dwarf cultivars to large trees. They make excellent garden plants.
Genus name is the Greek name for a kind of juniper (Juniperus.)
‘Green Giant’ is a fast-growing arborvitae hybrid cultivar (T. plicata x T. standishii) that is often promoted as a disease-free substitute for Leland cypress, particularly in the southeastern U.S. Trees may grow to 40-60’ tall with a dense, narrow, pyramidal habit, but can be kept more compact by pruning for screens or hedges. In the proper environment, trees can add up to 3-4’ of growth per year. Horizontal to slightly upright branching with sprays of scale-like dark green foliage. Foliage does not yellow in winter. Small, upright, light brown seed cones (to 1/2” long).
Problems
No serious insect or disease problems. Bagworm and rots may occur. Watch for scale.
Uses
Specimen for the lawn or foundation. Group in lawns or backgrounds. Young trees can be easily pruned as a hedge or screen.