The Green Tower Boxwood (Buxus sempervirens ‘Green Tower’) is a favored plant in many landscapes. This evergreen shrub is admired for its distinct columnar form and dense, deep green foliage that maintains its vibrancy throughout the year. Its naturally narrow and upright growth habit makes it a versatile choice for various garden designs, including hedges, vertical accents, or container plantings.
Understanding Green Tower Boxwood Growth Rate
The Green Tower Boxwood is generally considered a slow to moderate growing plant. Its typical annual growth rate ranges from approximately 4 to 6 inches, though some reports suggest up to 15 inches annually under ideal circumstances. It typically reaches a mature height of 7 to 9 feet with a narrow spread of 1 to 2 feet, taking several years to achieve its full size. Some can reach 8 to 10 feet in about seven years. The plant naturally maintains its slender, upright form, minimizing the need for extensive shaping.
Factors Influencing Green Tower Boxwood Growth
Several environmental and cultural factors influence the growth and overall health of Green Tower Boxwood. These boxwoods thrive in partial to full sun, ideally receiving at least 4 to 6 hours of direct sunlight daily. While they tolerate some shade, deep, dense shade is not recommended. They prefer well-draining, fertile soil with a pH between 6.0 and 7.5; avoid heavy clay or waterlogged areas to prevent root rot.
Consistent watering is crucial, especially for newly planted boxwoods, to establish a strong root system. Established plants are relatively drought-tolerant and require less frequent watering. Nutrient availability also supports robust growth; amending soil with organic matter like compost can improve fertility. Climate, specifically USDA hardiness zones 5 through 9, impacts their resilience, as they are hardy down to approximately -20°F. Pests and diseases, such as boxwood blight, root rot, leafminers, and psyllids, can impede growth and cause decline.
Managing Green Tower Boxwood for Desired Growth
To optimize the growth and health of Green Tower Boxwood, proper planting techniques are important. Dig a hole twice as wide as the root ball but no deeper, ensuring the top of the root ball is level with the surrounding soil surface. Incorporate organic compost into the planting area to enhance soil fertility and drainage. For hedges or screens, space multiple boxwoods at least 2 feet apart to allow for their mature width and promote good air circulation.
Watering should be consistent, especially during the first year after planting, providing deep and regular moisture to help establish strong roots. Once established, reduce frequency, but provide supplemental watering during dry periods. Apply a layer of organic mulch around the base to conserve soil moisture and regulate temperature, keeping it a few inches from the stem to prevent potential rot. Fertilization supports healthy development; a general-purpose, slow-release fertilizer applied in early spring before new growth begins is recommended.
Green Tower Boxwoods naturally maintain their columnar shape, so minimal pruning is typically required. Light shaping can be done in late winter or early spring before new growth emerges. Thinning cuts that allow more air and sunlight to reach the interior branches can promote overall health and reduce the risk of disease. When pruning, remove no more than one-third of the plant’s mass in a single season to avoid stressing the shrub.