Western red cedar (Thuja plicata 'Zebrina')

Overview

$Thuja\ plicata\ ‘Zebrina’$, commonly known as Western red cedar, is a highly valued variegated cultivar prized for its distinctive seasonal coloring. This form introduces feathery green foliage prominently striped with creamy yellow, providing excellent vertical interest throughout the growing season. As a slow-growing accent, this variety transforms any landscape with its unique texture and light accents.

Native to the moist forest areas of the Pacific Northwest, this specific cultivar maintains a relatively narrow, pyramidal habit, maturing in the 30 to 50-foot range. The aromatic, scale-like needles are a primary feature, releasing scent when crushed, making the Western red cedar a sensory addition to the garden. Gardeners appreciate this plant for its medium maintenance requirements and strong vertical presence.

While it is a majestic conifer, gardeners must situate $Thuja\ plicata\ ‘Zebrina’$ where cultural needs are met. It demands consistent moisture and well-drained soil to thrive, especially in hotter, drier climates outside its cool, native range. Success depends on providing the right habitat for this stunning variegated Western red cedar.

Fast Facts

• Plant Family: Cupressaceae
• Plant Type: Needled evergreen
• Hardiness Zones: USDA Zones 5-7
• Size at Maturity:
  • Height: 30-50 ft
  • Spread: 8-12 ft
• Bloom Time: Non-flowering
• Bloom Description: Non-flowering
• Sun Exposure: Full sun to part shade
• Water Needs: Medium
• Maintenance Level: Medium

How to Grow

The optimal time for planting $Thuja\ plicata\ ‘Zebrina’$ is generally in the spring or fall when temperatures are moderate. Choose a location that offers full sun exposure, though light afternoon shade is beneficial, particularly in regions experiencing intense summer heat. Essential to success is providing moist, fertile, and deeply well-drained soil; this plant absolutely cannot tolerate dry conditions.

Watering should be consistent, meeting its medium water needs, especially for establishing young specimens. Avoid letting the soil become waterlogged, which can lead to rot, but never allow the root zone to dry out completely. Fertilizing is seldom necessary if the soil is rich upon planting, but a balanced slow-release fertilizer in early spring can support robust growth.

Pruning is generally minimal as the ‘Zebrina’ form maintains a pleasing narrow pyramidal shape naturally. Focus pruning efforts on removing any dead or damaged wood in late winter or early spring before new growth begins. Be mindful that conditions outside its native habitat, such as the climate found in areas like St. Louis, may stress the Western red cedar, requiring closer monitoring of soil moisture and protection from extreme summer heat stress.

Landscape Uses

The distinctive vertical accent provided by $Thuja\ plicata\ ‘Zebrina’$ makes it an excellent choice for formal hedging where height and consistent structure are desired. Its variegated foliage brightens darker corners of the landscape, offering strong vertical punctuation against monolithic green backdrops. Due to its moisture demands, this Western red cedar is also well-suited for incorporation in rain gardens.

When planning garden companions, select plants that also prefer consistently moist, fertile soil and can tolerate its partial shade tolerance. Consider using broadleaf, colorful perennials or deciduous shrubs at its base to contrast the fine texture and evergreen structure of the $Thuja\ plicata\ ‘Zebrina’$. Its stately habit also works well as a specimen planting near entryways or focal points.

Standout Features

Noteworthy Characteristics

$Thuja\ plicata$, commonly called western red cedar or giant red cedar, is native to the Pacific Northwest where it is typically found in cool but moist forest areas and bottomlands from southern Alaska along the Pacific coast to northern California and in the northern Rockies from British Columbia to Montana. This is the largest tree in the cypress family, growing in its native habitat to 100-200’ tall and living from 400 to 1000+ years. ‘Zebrina’ is a variegated form of western red cedar which produces feathery green foliage striped with creamy yellow; it typically matures as a narrow pyramidal tree to 30-50’ tall and to 8-12’ wide.

Tolerances

• Clay Soil
• Black Walnut

Potential Problems

This particular cultivar of Western red cedar generally shows resistance to serious pest and disease issues when sited correctly. However, in suboptimal growing conditions (especially high heat combined with drought), issues like bagworm infestations or various root rots can occur. Gardeners should be particularly vigilant in non-native, drier climates, as environmental stress significantly lowers the plant’s resistance.

If you observe thinning foliage or dieback, immediately check soil moisture levels; inadequate or inconsistent water is the most common culprit for health decline in this species. Ensuring excellent drainage, even in heavy clay soil, is crucial for preventing fungal rots, which thrive in persistently saturated conditions. Promptly prune out any visible signs of disease or pest damage to maintain the health of your $Thuja\ plicata\ ‘Zebrina’$.

Frequently Asked Questions

What hardiness zones is Western red cedar suitable for?

The cultivar $Thuja\ plicata\ ‘Zebrina’$ is recommended for USDA Hardiness Zones 5 through 7, requiring protection or careful siting outside this range.

How large does Western red cedar grow?

This specimen typically reaches a mature height between 30 and 50 feet tall, with a relatively narrow spread of 8 to 12 feet.

What sun exposure does Thuja plicata ‘Zebrina’ need?

This conifer performs best in full sun, although it benefits greatly from some light afternoon shade, especially during the hottest part of the summer.

When does Thuja plicata ‘Zebrina’ bloom?

This needled evergreen is non-flowering; it does not produce noticeable flowers as part of its ornamental cycle.

Conclusion

The striking variegation of $Thuja\ plicata\ ‘Zebrina’$ offers unique light and texture, making the Western red cedar a standout choice for vertical accents and structured hedges in suitable climates. Remember that this conifer requires consistent moisture and well-drained soil compared to many hardier evergreens. Before planting, verify that your growing conditions align with USDA Zones 5-7 and plan for adequate moisture management to ensure the vibrant yellow stripes shine for years to come.

Companion Planting

When designing beds around your $Thuja\ plicata\ ‘Zebrina’$, select neighbors that share the need for moist, rich soils, avoiding extremely xeric plants. Hydrangeas, Astilbes, and certain moisture-loving ferns make excellent lower-layer companions, complementing the fine texture of the cedar. Consider using plants with dark green or burgundy foliage directly beneath the ‘Zebrina’ to emphasize the contrast of its creamy yellow striping.

Seasonal Care Calendar

Spring preparation is vital for setting up the season successfully. Apply a slow-release, balanced fertilizer as buds begin to swell, and begin consistent deep watering once the risk of hard frost has passed. Summer care focuses almost entirely on water management; never let the soil dry out during periods of sustained heat, as desiccation is the biggest threat to this Pacific Northwest native. In autumn, ensure a deep watering before the ground freezes to prepare the Western red cedar root system for winter dormancy.