What Is the Wintergreen Boxwood Growth Rate?

The Wintergreen Boxwood, or Buxus sinica var. insularis ‘Wintergreen’, is a popular evergreen shrub known for its hardiness and versatility. Its dense foliage maintains a vibrant green color through winter, making it a reliable choice for creating structure in the landscape. It is frequently used for low hedges, foundation plantings, and formal borders. Understanding its growth rate informs proper spacing and long-term maintenance.

Typical Growth Rate of Wintergreen Boxwood

The Wintergreen Boxwood has a slow to moderate growth rate, a desirable trait for many landscape applications. Annually, the shrub adds between 2 to 4 inches in height and width, though some may reach up to 6 inches per year under optimal conditions. This pace is faster than many dwarf English boxwood varieties.

This controlled growth makes the Wintergreen relatively low-maintenance, as its predictable development allows for precise planning in formal gardens. This ensures it will not quickly overwhelm its designated space and does not demand frequent, intensive pruning to keep it in check.

Mature Size and Growth Timeline

An unpruned Wintergreen Boxwood reaches a mature size of 3 to 4 feet tall and spreads 4 to 5 feet wide. Its natural form is a dense, rounded mound, but it is often pruned for a more compact shape. This size is excellent for creating hedges that define spaces without becoming imposing barriers.

To set realistic expectations, consider that a 12-inch nursery plant growing 3 inches per year will take about 8 years to reach a 3-foot height. This gradual progression allows the plant to establish a strong root system and dense foliage, resulting in a healthier, more robust specimen over time.

Factors That Influence Growth Speed

Sunlight

This boxwood performs best in full sun to partial shade, receiving at least four to six hours of direct sunlight daily. While it tolerates full shade, growth will be slower and the foliage less dense. In regions with intense summer heat, too much direct sun can scorch the leaves and impede development.

Soil

Wintergreen Boxwood thrives in well-drained soil that is not overly sandy or heavy in clay. The ideal composition is a moist, sandy loam with a pH that is slightly acidic to neutral. Poorly drained soils can cause water to accumulate around the roots, leading to root rot and stunted growth.

Watering

Newly planted boxwoods need consistent moisture to establish a robust root system. Water them every couple of days for the first few weeks, then taper to once a week as new growth appears. Once established, they are drought-tolerant but grow best with regular watering, especially during extreme heat.

Fertilizing

Apply a balanced, slow-release fertilizer, such as a 10-10-10 formula, in early spring just before new growth emerges. This timing provides the necessary nutrients when the plant enters its active growth phase.

Pruning to Manage Growth

Pruning is a method for managing the size and shape of a Wintergreen Boxwood, not for accelerating its growth. The best time to prune is in late winter or early spring, after the last frost but before new growth begins. This timing prevents frost from damaging the tender new shoots.

For formal hedges, shearing is the common practice and involves trimming the outer foliage to create a dense surface. An alternative is thinning, which is the selective removal of older, interior branches. This technique improves air circulation and light penetration, promoting healthier growth and reducing disease risk.