Thuja occidentalis ‘Degroot’s Spire’ (American Arborvitae)

Thuja occidentalis ‘DeGroot’s Spire’ (American Arborvitae) stands out for its columnar shape and rich green foliage, making it a versatile and visually appealing addition to a wide range of landscape designs. Its adaptability and ease of care make it a favorite among gardeners and landscapers alike.

Thuja occidentalis ‘DeGroot’s Spire’: An In-depth Look

Thuja occidentalis ‘DeGroot’s Spire’ is an attractive and distinctive cultivar known for its narrow, columnar form and dense, rich green foliage. It is a popular choice for vertical accents in landscapes.

Native: Thuja occidentalis is native to North America. It is predominantly found in the northeastern United States and southeastern Canada. This species naturally occurs in wet forests, swamps, and along lake shores, thriving in cool, moist, well-drained environments.

Plant Type and Habit: This is a coniferous evergreen tree with a unique, upright, and slender growth habit, making it ideal for narrow spaces.

Size: Slow-growing, ‘DeGroot’s Spire’ can reach a height of 20-30 feet (6 to 9 meters) and a spread of 4-6 feet (1.2 to 1.8 meters) in 15-20 years.

Foliage: The foliage consists of twisted, feathery sprays of rich green scales that takes on a purple tinge in winter. When you bruise the foliage, it gives off a very pleasant fragrance reminiscent of citrus.

Bark: The bark is reddish-brown, relatively smooth, and becomes more textured with age.

Uses: Ideal for formal gardens, hedges, screens, and as a vertical accent in mixed borders or foundation plantings. Its narrow form is especially useful in tight spaces.

Hardiness: Hardy in USDA zones 3-8, it can withstand cold winters and a range of environmental conditions.

Wildlife: Provides limited shelter for small wildlife.

Toxicity: Generally considered non-toxic to humans and animals.

Deer and Rabbit: May suffer some damage from deer and rabbits, especially in areas where these animals are prevalent.

Invasiveness: This cultivar is not considered invasive and typically stays within its planted boundaries.

Benefits: It offers vertical interest in landscape design, is relatively low-maintenance, and provides year-round foliage color.

American Arborvitae Growing Tips

Light: Thrives in full sun but can also grow well in partial shade. Full sun exposure leads to denser foliage growth. Usually appreciates some light afternoon shade in hot summer climates. Protect from drying winds, especially when young.

Soil: Adaptable to a wide range of soils but prefers moist, well-drained, slightly acidic to neutral soil. Tolerates clay soils.

Water: Regular watering is important, especially for young plants and in dry conditions. Avoid extreme dry soil in the fall, which can cause the evergreen foliage to dry out in winter.

Fertilizer: Apply a balanced, slow-release fertilizer in early spring. Over-fertilization can harm the plant, so follow the recommended rates.

Pruning: Little to no pruning is required. Prune for shaping or size control in late winter or early spring before new growth starts. Avoid heavy pruning.

Mulch: Provide a generous root zone mulch.

Propagation: Propagated through semi-hardwood cuttings in late summer.

Pests and Diseases: Watch for bagworms, spider mites, mealybugs, and scale insects. Leaf tips may suffer damage from leaf miners. Canker can sometimes pose a problem. Fungal diseases like root rot can occur in poorly drained soils. Good air circulation and proper planting depth help prevent these issues.