Thuja × 'Green Giant' (Arborvitae 'Green Giant') is a vigorous, large evergreen commonly planted for quick privacy, windbreaks, and year-round screening. You get dense, deep green, scale-like foliage held in flat sprays on a naturally uniform, columnar-pyramidal plant that stays attractive with minimal shaping.
Plan for a mature size around 30-50 ft tall and roughly 12-16 ft wide (based on a typical spread of 12-16 ft). Give it room so you are not forced into constant heavy pruning later. If you are building a screen, spacing depends on how quickly you want closure, but adequate airflow and room for mature width help keep plants healthier and easier to maintain.
For best results, plant in full sun to part shade. You will get the most dense growth with more sun, while light afternoon shade can help in hotter sites. It adapts to a range of soils as long as drainage is reasonable. After planting, keep the root zone evenly moist while it establishes; once established, it can handle occasional dry spells better, but it still looks best with consistent moisture during extended drought.
Mulch to moderate soil temperature and conserve moisture, keeping mulch a few inches off the trunk. Prune lightly (if needed) to keep a clean outline, and avoid cutting back into old, leafless wood. With its fast growth and evergreen habit, this plant is a strong choice when you want a tall, living wall without a lot of fuss.