American arborvitae (Thuja occidentalis 'Ericoides')

Overview

The Thuja occidentalis ‘Ericoides’, commonly known as American arborvitae, is a compact and aesthetically pleasing needled evergreen valued for its dense, globular habit. Unlike its larger relatives, this cultivar remains small, making it highly versatile for low-maintenance garden designs. Its foliage is slightly juvenile, featuring soft, needle-like leaves that offer excellent texture contrast against traditional scale-like evergreens.

A key feature of this slow-growing shrub is its winter color transition; the yellowish-green summer foliage takes on attractive purplish-brown tones when cold weather arrives. This dependable year-round interest and extremely low maintenance requirements make Thuja occidentalis ‘Ericoides’ a standout choice for targeted plantings where space is a consideration.

As a durable specimen, the American arborvitae manages a wide range of soil conditions, though it performs best with consistent moisture. Its resilience, particularly against urban stresses, ensures that the Thuja occidentalis ‘Ericoides’ remains a practical and beautiful structure in many landscapes.

Fast Facts

• Plant Family: Cupressaceae
• Plant Type: Needled evergreen
• Hardiness Zones: USDA Zones 2-7
• Size at Maturity:
  • Height: 3-6 ft
  • Spread: 3-6 ft
• Bloom Time: Non-flowering
• Bloom Description: Non-flowering
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Low

How to Grow

Plant Thuja occidentalis ‘Ericoides’ in the spring or fall to allow roots time to establish before seasonal extremes. Select a site providing full sun, though light afternoon shade is beneficial in hot summer climates. While this American arborvitae tolerates a somewhat wide range of soils, aim for average, medium moisture, well-drained loams that are neutral to slightly alkaline for optimal health. Avoid locations prone to dryness, as this plant is intolerant of drought conditions.

Water regularly after planting until the root system is well-established, typically equating to medium water needs during the growing season. Once mature, supplemental watering may only be necessary during prolonged dry spells. Due to its low maintenance requirement, fertilizing is rarely crucial; however, a light application of balanced evergreen feed in early spring can support vigorous growth if soils are poor. Pruning is minimal, primarily restricted to removing any damaged wood, as shaping the natural globe habit is rarely necessary.

Be mindful of site selection regarding wind exposure; avoid exposed, windy sites which can increase the risk of winter burn, causing the foliage to turn yellow-brown. In areas with heavy winter snow or ice, gently brush off heavy accumulations to prevent potential branch breakage in the dense structure of the Thuja occidentalis ‘Ericoides’. Minimize planting in full shade, as this will substantially decrease foliage density.

Landscape Uses

The compact, globular form of the American arborvitae makes Thuja occidentalis ‘Ericoides’ exceptionally useful in structured and formal garden settings. It excels when used as foundation plantings, providing low-lying, year-round green texture directly next to buildings where height might obscure windows. Its tight habit keeps shearing needs low, reducing long-term labor.

These evergreens are also perfect for rock gardens, adding necessary vertical contrast among low-growing perennials and alpines. Furthermore, the Thuja occidentalis ‘Ericoides’ shines as an accent plant, providing a permanent, dark green anchor in mixed perennial borders or specialty beds. Because they handle containers well, they are ideal for balcony gardening or defining entryways on a repeating pattern.

Consider pairing this evergreen with deciduous shrubs that offer vibrant fall color or spring flowers, allowing the static texture of the American arborvitae to highlight seasonal changes in neighboring plantings. Their dark color also provides an excellent backdrop for flowering annuals.

Standout Features

Noteworthy Characteristics

Thuja occidentalis, commonly known as American arborvitae, Eastern arborvitae, Eastern white cedar or Northern white cedar, is a dense, conical to narrow-pyramidal (sometimes maturing to broad-pyramidal), often single-trunked, evergreen tree that is native to eastern and central Canada south to northern Illinois, Ohio and New York with scattered populations further south in the Appalachians to North Carolina. Mature trees may reach 40-60’ tall in the wild over time, but in cultivation typically grow much smaller to 20-30’ tall. Scale-like, aromatic, yellow-green to green foliage appears in flattened sprays. Red-brown bark will exfoliate on mature branches and trunks.Genus name is the Greek name for a kind of juniper (Juniperus.)Specific epithet means from the Western (Occidental) world. The common name of arborvitae (tree of life) comes from early French settlers to North America who learned from Native Americans that the tree’s foliage could be used to treat scurvy. ‘Ericoides’ is a slow-growing, dense, globular, evergreen shrub that grows to 30” tall and 36” wide in the first 10 years. It is a juvenile form with soft, needle-like, yellowish-green to dull green leaves that turn purplish-brown in winter.

Tolerances

• Clay Soil
• Black Walnut
• Air Pollution

Potential Problems

Foliage issues are typically cosmetic but require attention to improve condition. Leaf blight can cause spotting and subsequent leaf drop, while leaf miners occasionally damage leaf tips. Routine scouting for pests such as bagworms, mealybugs, scales, and spider mites is recommended, especially if the plant is stressed.

Winter weather can present its own challenges for the American arborvitae. Foliage may exhibit winter burn, turning yellow-brown in areas exposed to drying winter winds or intense sun reflecting off snow. Furthermore, the dense structure is susceptible to physical damage from heavy ice or snow accumulation, leading to stem breakage. Proper placement away from high winds can mitigate these aesthetic concerns.

Frequently Asked Questions

What hardiness zones is American arborvitae suitable for?

This specific cultivar, Thuja occidentalis ‘Ericoides’, thrives in a wide range, suitable for USDA Zones 2 through 7.

How large does Thuja occidentalis ‘Ericoides’ grow?

It is a smaller shrub, typically reaching mature heights between 3 to 6 feet tall, with an equivalent spread of 3 to 6 feet.

What sun exposure does American arborvitae need?

The Thuja occidentalis ‘Ericoides’ prefers full sun but tolerates light shade; however, avoid deep shade which reduces its foliage density.

When does American arborvitae bloom?

This plant is a needled evergreen and is non-flowering.

Conclusion

The Thuja occidentalis ‘Ericoides’ offers gardeners a robust, low-maintenance evergreen solution with a unique, soft texture and manageable size. Its ability to tolerate clay, pollution, and drought stress (once established) secures its spot as a reliable performer. Before planting, confirm your site falls within USDA Zones 2-7 and ensure a spot offering adequate sun exposure to fully appreciate the tight, globular habit of this excellent American arborvitae selection.

Companion Planting

When designing beds around Thuja occidentalis ‘Ericoides’, focus on companions that contrast nicely with its deep green, fine texture. Plants that offer bright seasonal color work exceptionally well next to this low, dense shrub. Consider pairing it with late-flowering perennials like Russian Sage (Perovskia atriplicifolia) or low-mounding Sedums, which thrive in similar sun and tolerance conditions. For year-round interest, use broadleaf evergreens like dwarf Rhododendrons or Japanese Hollies near the base, ensuring good air circulation between the two types of evergreens.

Container Growing

The excellent size and shape profile of this cultivar make it outstanding for container use, either as a single specimen or as the central ‘thriller’ element in a mixed arrangement. When growing Thuja occidentalis ‘Ericoides’ in pots, remember that containerized plants dry out faster than those in the ground, so monitor the medium closely to meet its medium water needs. Use a high-quality potting mix designed for evergreens, and ensure that the container has flawless drainage to prevent root issues, as excess moisture is detrimental. Protect containers in Zone 2 climates by insulating or moving them to a sheltered location for the winter months.