The Green Mound Boxwood (Buxus microphylla ‘Green Mound’) is a popular, compact, and adaptable evergreen shrub. Cherished for its dense foliage and versatile nature, it provides year-round greenery and structure with minimal effort.
Green Mound Boxwood Characteristics and Benefits
The Green Mound Boxwood typically reaches 2 to 3 feet tall and wide, though it can grow to 4-5 feet over many years. It has a naturally rounded, mounding growth habit, making it an excellent choice for structured plantings. Its small, glossy, dark green leaves, up to 3/4 inch long, retain their vibrant color year-round.
This plant’s compact, spherical shape requires minimal shaping. It has a slow to moderate growth rate (2-3 inches per year), which reduces the need for frequent pruning. Green Mound Boxwood is cold-hardy in USDA Zones 4 to 9 and resists deer and rabbits.
Planting and Basic Care
Green Mound Boxwood thrives in full sun to partial shade. Full sun and strong winds can cause winter bronzing, while shadier conditions may result in less vigorous, more open foliage. The ideal soil is evenly moist, well-drained loam with a pH between 6.5 and 7.0.
When planting, dig a hole two to three times wider than the root ball and just as deep. Position the plant so the top of the root ball is level with or slightly above the surrounding soil. Backfill the hole, tamping gently to remove air pockets, then water thoroughly to settle the soil.
Consistent moisture is important, especially for new plants. Water deeply when the top inch of soil is dry, ensuring the root zone remains moist but not waterlogged to prevent root rot. Established plants are more drought-tolerant but benefit from weekly watering during dry periods, even in winter. Apply a 1-2 inch layer of organic mulch around the base to retain moisture and protect shallow roots, keeping it away from the trunk.
Fertilize in early spring and mid-summer with a balanced, slow-release evergreen fertilizer. A soil test can help determine specific nutrient needs. Boxwoods do not require excessive fertilization.
Pruning and Shaping
Prune Green Mound Boxwood in late spring or early summer, after new growth has hardened and after the last frost. Pruning too early can stimulate tender new growth susceptible to frost damage. Light, frequent trimming is preferred over heavy pruning to maintain density and avoid stressing the plant.
For maintenance, remove dead, damaged, or diseased branches to promote health and air circulation. Light shearing can shape the plant or create formal hedges and topiaries. Thinning increases airflow and sunlight penetration, reducing disease risk.
Common Issues and Solutions
Green Mound Boxwood can encounter several common issues. Boxwood blight, a fungal disease, causes leaf spots, rapid defoliation, and black cankers on stems. If detected, remove and destroy infected plant material and any fallen leaves, and sanitize pruning tools to prevent spread. Volutella blight presents with browning leaves and scattered branch dieback, where infected foliage remains on the plant, and salmon-colored fungal spores might be visible. Improving air circulation through thinning and avoiding overhead irrigation can help prevent fungal diseases.
Root rot, caused by fungal pathogens, occurs in poorly drained or consistently wet soils, leading to poor growth, discolored leaves, and a reduced root system. Ensuring well-drained soil and avoiding overwatering are key preventative measures. Pests like boxwood leafminer, boxwood psyllid, and spider mites can also affect the plant. Symptoms often include yellowing, curling leaves, or a general decline in vigor. Regularly inspecting plants can help identify issues early, and maintaining plant health through proper care can deter pest infestations.
Landscaping Applications
The Green Mound Boxwood’s compact size and evergreen nature make it versatile in landscape design. It is frequently used to create low hedges that define borders or pathways, adding a tidy and uniform appearance. Its dense form also makes it an excellent choice for foundation plantings around buildings, offering year-round structure and a polished look.
This shrub is suitable as an accent plant in mixed beds or rock gardens, providing a constant green element among seasonal plantings. Its adaptable size allows it to thrive in containers, making it perfect for patios, entryways, or as a decorative accent. It can also be shaped into small specimens or used for edging in formal garden designs.