Mr. Bowling Ball Arborvitae, scientifically known as Thuja occidentalis ‘Mr. Bowling Ball’ or ‘Bobozam’, is a compact, spherical evergreen shrub prized for its distinct shape and fine-textured foliage. This dwarf conifer naturally forms a dense, rounded globe with soft, sage-green to blue-green needles, providing year-round color. Its tidy, compact habit makes it a low-maintenance, aesthetically pleasing choice for various landscape applications.
Understanding Essential Care
Optimal growth for Mr. Bowling Ball Arborvitae depends on meeting its specific environmental needs. Providing consistent care ensures the plant remains healthy and maintains its appealing form.
Light Needs
Mr. Bowling Ball Arborvitae performs best in full sun, requiring at least six hours of direct sunlight daily. While it tolerates partial shade, too little sun may result in less dense foliage. In hotter climates, afternoon shade can help prevent stress and maintain vibrant foliage color.
Soil Preferences
This arborvitae thrives in well-drained soil that retains moderate moisture. It adapts to various soil types, including clay, but good drainage is essential to prevent waterlogging. The preferred soil pH is slightly acidic to neutral, though it tolerates a range from alkaline to neutral.
Watering Guidelines
Consistent moisture is important for Mr. Bowling Ball Arborvitae, especially during establishment. Newly planted shrubs require deep watering once or twice a week for the first six weeks to establish a strong root system. For established plants, water deeply when the top two to three inches of soil feel dry, adjusting frequency based on rainfall and temperature. Proper watering prevents stress and root issues.
Fertilizing Practices
Mr. Bowling Ball Arborvitae has low fertilizer requirements. Applying a balanced, slow-release fertilizer in early spring can support healthy growth, particularly for young plants or those in nutrient-poor soil. Established plants often maintain good health without heavy fertilization, but a top-dressing of compost every other year can enhance soil quality.
Proper Planting and Establishment
Proper planting techniques and timing ensure successful establishment of Mr. Bowling Ball Arborvitae. Spring or fall’s cooler temperatures are ideal for planting, allowing roots to acclimate before extreme weather. Effective site preparation promotes healthy growth.
To plant, dig a hole at least twice as wide as the root ball but no deeper. Position the shrub so the top of the root ball is level with or slightly above the surrounding soil, ensuring the root flair is visible. Backfill with soil, gently tamping to remove large air pockets, then water thoroughly to settle the soil. Apply a two to three-inch layer of organic mulch around the base, keeping it a few inches away from the trunk, to retain soil moisture and regulate temperature.
Pruning for Shape and Health
Mr. Bowling Ball Arborvitae naturally maintains its spherical shape, minimizing the need for extensive pruning. This makes it a low-maintenance shrub. Light pruning can be performed in late winter or early spring, before new growth begins, to remove dead, damaged, or crossing branches.
When shaping is desired, trim only the new growth of the current season to avoid cutting into old wood, as arborvitae does not readily regrow from bare branches. Prune no more than 10-15% of the total foliage to prevent stressing the plant. This approach promotes overall health.
Addressing Common Issues
While Mr. Bowling Ball Arborvitae is generally resilient, it can encounter problems affecting its appearance and health. Browning foliage is a common concern, often caused by drought stress, winter burn from cold winds and sun, or transplant shock. Ensuring consistent moisture and providing protection in harsh conditions can mitigate these issues.
Pests such as spider mites, bagworms, and scale insects can infest arborvitae. Spider mites cause stippled or dull foliage with fine webbing. Bagworms create silken bags of foliage that can defoliate the plant. Scale insects are sap-feeding pests leading to yellowing needles and sticky residue.
Diseases like root rot occur in poorly drained or overly wet soils, causing wilting or browning. Proper watering and soil drainage are key preventative measures against root rot.
Winter Protection
Although Mr. Bowling Ball Arborvitae is hardy in USDA Zones 3-8, providing some winter protection can be beneficial, especially in colder climates. Ensuring the plant is well-hydrated before the ground freezes helps prevent winter burn from moisture loss in evergreen foliage during dry, cold conditions. Watering deeply in late fall helps the plant store moisture for winter.
Applying a two to three-inch layer of mulch around the root zone insulates the soil and protects roots from freezing temperatures. In areas with heavy snow or ice, gently brushing off accumulation prevents branch breakage. These measures contribute to the arborvitae’s continued health and appearance through the colder season.