Westmont Chinese Arborvitae (Platycladus orientalis ‘Westmont’) is an evergreen shrub or small tree valued for its unique growth characteristics and adaptability in diverse garden designs. Understanding its specific needs helps cultivate a thriving and visually appealing plant.
Understanding Westmont Chinese Arborvitae
Westmont Chinese Arborvitae is a compact, slow-growing evergreen shrub, recognized for its naturally rounded or globe-shaped habit. It typically reaches a mature height of 2 to 3 feet and a spread of 1.5 to 2 feet. Growing only about 2 inches per year, it maintains its size with minimal intervention.
Its foliage is dark green with bright yellow or golden tips. These scale-like leaves may develop a coppery-bronze tint during colder winter months, adding seasonal interest. This plant is hardy in USDA Zones 6 through 9.
Planting and Ongoing Care
Site Selection
Westmont Chinese Arborvitae thrives in full sun to partial sun, requiring at least six to eight hours of direct sunlight daily. In regions with intense summer heat, afternoon shade can prevent foliage stress. It prefers well-draining soil, including sandy loam, clay loam, chalky, or rocky compositions. Good air circulation is also beneficial.
Planting Process
When planting, prepare a hole twice the width of the root ball and at the same depth as its nursery container. Carefully remove the plant and gently separate any circling roots to encourage outward growth. Backfill the hole using original soil, or a mix with compost if soil quality is poor. Create a water ring around the perimeter of the planting hole and apply a 3-inch layer of organic mulch.
Watering
Water deeply and regularly throughout the first growing season to establish an extensive root system. Water when the top 2 inches of soil feel dry, typically once or twice a week. Newly planted arborvitae may need approximately 1.3 to 1.9 gallons of water weekly during dry periods. Once established, Westmont Chinese Arborvitae becomes more drought tolerant, but consistent deep watering at the base of the plant, avoiding foliage, remains beneficial.
Fertilizing
Fertilization supports vigorous growth, with early spring before new growth emerging as the best time for application. Young plants benefit from fertilizers with higher phosphorus for strong root development. Established plants may benefit from fertilization every few years or annually, depending on soil conditions and vigor. A balanced, slow-release fertilizer is generally suitable; a soil test can provide specific nutrient recommendations. Avoid fertilizing late in the growing season, as this can stimulate tender new growth vulnerable to cold weather.
Pruning
Westmont Chinese Arborvitae generally requires minimal pruning due to its natural globe shape. Annual pruning in late winter or early spring, before new growth begins, can help maintain its desired size and shape. Remove any dead, diseased, or crossing branches by cutting them back to their origin. For a more formal appearance, the plant can be lightly sheared to maintain its compact form.
Ideal Landscape Uses
The compact size and distinct globe shape of Westmont Chinese Arborvitae make it a versatile addition to many landscape designs. It is ideal for:
- Low hedges, providing clear boundaries or defining garden spaces.
- Foundation plantings, offering year-round evergreen interest close to structures.
- Rock gardens or as a specimen plant, highlighting its unique form and foliage.
- Accent plant, drawing attention to specific garden areas.
- Containers, formal rows, or grouped in pairs for symmetrical arrangements.
Addressing Common Challenges
Westmont Chinese Arborvitae is generally robust, but can encounter issues. Foliage browning may occur due to environmental stressors like winter desiccation, drought, or extreme heat. In winter, foliage may naturally bronze as a normal seasonal change. Adequate watering, especially during dry spells, helps mitigate browning from drought.
The plant can be susceptible to common pests, including:
- Spider mites
- Bagworms
- Scales
- Aphids
- Caterpillars
- Borers
- Mealybugs
Good cultural practices, such as proper watering and air circulation, help maintain plant health and reduce susceptibility. Root rot can develop in excessively wet conditions or poorly draining soil. Branches may also be prone to breakage under heavy snow loads, and protection from strong drying winter winds is beneficial.