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Cork Arborvitae

Scientific Name​

Platycladus orientalis

Description​

Cork Arborvitae, scientifically known as Thuja occidentalis 'Corthzita', is a compact, evergreen conifer that belongs to the cypress family. This attractive plant is well-regarded for its unique, cork-like texture on the bark and lush, dense foliage. Often used in landscaping, it serves as an ideal choice for hedges, borders, or specimen plants due to its ornamental appeal and adaptability.

The Cork Arborvitae typically reaches a height of 3 to 5 feet and can spread up to 2 to 3 feet, making it suitable for smaller gardens or as a foundation plant in larger landscapes. Its foliage is a rich green, with scale-like leaves that provide year-round visual interest and a pleasant scent when brushed against. In the fall, the foliage can take on a slight bronze hue, adding seasonal color.

This plant is hardy in USDA zones 3 to 7, making it suitable for a variety of climates. It prefers full sun to partial shade and thrives in well-drained soil with moderate moisture. Due to its drought resistance once established, the Cork Arborvitae requires less maintenance compared to some other shrubs, making it a favorite among busy gardeners.

In addition to its aesthetic qualities, it also attracts birds and other wildlife, contributing to local biodiversity. Overall, the Cork Arborvitae is a versatile, low-maintenance plant that brings beauty and structure to gardens while providing ecological benefits.

Where it Grows​

When to Plant​

Planting Cork Arborvitae: Timing and Considerations​

The Cork Arborvitae, Thuja plicata 'Atrovirens', is a popular evergreen shrub known for its dense foliage and ability to withstand various environmental conditions. To ensure the successful establishment of your Cork Arborvitae, it's crucial to understand the ideal timing for planting.

Optimal Planting Time​

The best time to plant Cork Arborvitae is during the early spring or early fall. These seasons provide milder temperatures and increased moisture, which are beneficial for root development.

  1. Spring Planting: Early spring (around March to April) is advantageous as it allows the plant to take advantage of the growing season. The soil temperatures are warming, and there is often more rainfall, which creates a conducive environment for roots to establish before summer heat.

  2. Fall Planting: Early fall (from late September until mid-October) is another excellent time for planting. This timeframe allows the Cork Arborvitae to take root and acclimate before the winter months. Ensure to plant at least a month before the ground freezes, giving the roots time to settle in.

Factors to Consider​

  • Climate Zone: Cork Arborvitae thrives in USDA Hardiness Zones 5-8. Knowing your zone can help you determine when the threat of frost has passed or will arrive, thus guiding your planting schedule accordingly.

  • Soil Condition: Before planting, check the soil moisture. It should not be overly saturated or dry. If the soil is too wet or too dry, it can impair root establishment.

  • Weather Patterns: Keep an eye on extended weather forecasts. Planting right before a heatwave can stress your new arborvitae. Look for a window of cooler, cloudy days for planting.

  • Local Recommendations: Sometimes, local gardening centers or extension services provide specific advice based on regional conditions. Don’t hesitate to consult them for tailored guidance.

By considering these factors and choosing the right planting time, you can promote healthy growth and longevity of your Cork Arborvitae, setting the foundation for a beautiful addition to your landscape.

How to Plant​

Planting a Cork Arborvitae (Thuja plicata 'Green Giant') requires careful attention to ensure optimal growth and health. Ideally, the best planting time is during early spring or fall when temperatures are moderate.

Start by selecting a location with full sun to partial shade, as this plant thrives best in well-drained, fertile soils. Before planting, dig a hole that is twice as wide and as deep as the root ball of the tree. This encourages the roots to spread out easily.

Soak the root ball in water for about 30 minutes prior to planting to ensure it is adequately hydrated. When placing the Cork Arborvitae in the hole, ensure that the top of the root ball is level with the surrounding soil. Backfill the hole with native soil, gently patting it down to eliminate air pockets. Avoid compacting the soil too tightly.

Water the newly planted tree thoroughly to settle the soil, and then apply a layer of mulch around the base to retain moisture and suppress weeds. Regular watering during the first growing season is essential to establish a strong root system. With proper care, the Cork Arborvitae can grow into a stunning, hardy addition to your landscape.

Watering​

Cork Arborvitae (Thuja plicata 'Grove Creative') thrives best with a careful watering strategy, particularly during its establishment phase. Initially, new plantings require consistent moisture to develop strong roots. Watering deeply and infrequently is recommended, ensuring the soil is moist 6-12 inches down rather than applying frequent light waterings that can encourage shallow root systems.

During the first growing season, aim to water once or twice a week, depending on rainfall and soil drainage. After the plant is established, typically after one year, the Cork Arborvitae can tolerate some drought but will still benefit from periodic deep watering, especially during hot, dry spells. Mulching around the base helps retain soil moisture and regulate temperature. Always check the soil moisture before watering; the top couple of inches should be dry but not completely parched. Adjust your watering schedule according to seasonal changes and the specific climate conditions in your area.

Pruning​

Pruning a Cork Arborvitae (Platycladus orientalis) requires a strategic approach to maintain its shape and promote healthy growth. The best time to prune is late winter or early spring before new growth begins. Start by removing any dead, damaged, or diseased branches to encourage better airflow and light penetration. Focus on thinning the interior of the plant to prevent overcrowding; this enhances overall health and reduces the risk of pests and diseases.

When shaping, aim to keep the natural conical form of the tree. Trim back the outer branches lightly rather than shearing the entire plant, which can lead to unsightly gaps. Always use clean, sharp pruning shears to ensure clean cuts that heal properly. By following these guidelines, you’ll help your Cork Arborvitae thrive while preserving its characteristic beauty and form. Regular maintenance every couple of years will keep it healthy and attractive in your landscape.

Weeding​

Weeding around the Cork Arborvitae (Thuja plicata 'Nana') is essential for maintaining its health and aesthetics. The best strategy involves several key steps.

First, start by applying a thick layer of mulch (2-3 inches) around the base of the plant. This helps suppress weed growth and retains moisture. When it comes to manual weeding, it’s best to do so by hand or with a hand hoe, as the roots of the Cork Arborvitae can be shallow and easily disturbed by aggressive tools.

Weed after rainfall or watering when the soil is soft, making it easier to remove the entire root system. Focus on pulling weeds when they are small to prevent them from going to seed. Additionally, regular monitoring and removing any emerging weeds will help keep the area surrounding the Cork Arborvitae healthy and thriving. Regular maintenance will foster a cleaner garden bed and promote better growth of your tree.

Mulching​

Mulching is an essential practice for maintaining the health of a Cork Arborvitae (Thuja plicata 'Gelfand'), especially in the first few years after planting. The best strategy involves the following steps:

  1. Timing: Apply mulch in spring or fall, taking care to time it when the soil is moist to help retain moisture.

  2. Material: Use organic materials like shredded bark, wood chips, or pine needles. These not only suppress weeds but also improve soil quality as they decompose.

  3. Depth: Spread the mulch evenly around the base of the plant, maintaining a depth of 2 to 4 inches. Avoid piling mulch against the trunk, as this can lead to rot.

  4. Radius: Extend the mulch out to the drip line of the tree if possible, ensuring coverage in the critical root zone.

  5. Maintenance: Periodically replenish the mulch as it decomposes to maintain effectiveness and ensure moisture retention.

Following these guidelines can promote healthy growth and resilience in your Cork Arborvitae.

Fertilizing​

When fertilizing a Cork Arborvitae (Thuja pilcata), timing and type of fertilizer are crucial for optimal growth. The best strategy involves using a slow-release, balanced fertilizer, ideally in early spring as new growth begins. A formulation with equal ratios of nitrogen, phosphorus, and potassium—such as a 10-10-10—can effectively promote healthy foliage and root development.

Before application, ensure the soil is moist to prevent root burn. Spread the fertilizer evenly around the base of the plant, avoiding direct contact with the trunk, and follow the manufacturer’s recommended dosage. Water the area well after applying the fertilizer to help it penetrate the soil.

It's important not to over-fertilize, as this can lead to excessive growth or weakened plants. Monitoring the health of your Cork Arborvitae and adjusting the feeding schedule annually based on its growth and environmental conditions will further enhance its vitality.

Varieties​

Common Varieties of Cork Arborvitae​

Cork Arborvitae, scientifically known as Thuja plicata, is a conifer that belongs to the cypress family. Known for its unique, cork-like bark and vibrant green foliage, it is a popular choice in landscaping and gardening. Below are some of the common varieties of Cork Arborvitae that gardeners often consider.

1. Green Giant​

The Green Giant variety is known for its fast growth rate and dense, pyramidal shape. It can reach heights of up to 60 feet and is often used for privacy screens or windbreaks. This variety is well-adapted to a range of soil types but prefers well-drained soil and full sun.

2. Emerald Green​

The Emerald Green variety is smaller than the Green Giant, typically growing to about 12-15 feet tall. It showcases a lush, vibrant green color and has a narrower, conical shape, making it an excellent choice for smaller gardens or as a foundation plant. This variety is also preferred for its resistance to cold temperatures.

3. Pendula​

Pendula is a unique weeping variety that features graceful, pendulous branches. This slow-growing form typically reaches heights of about 5-10 feet and is ideal for artistic landscaping or adding visual interest to a garden. Due to its distinctive shape, it can function as a focal point in garden design.

4. Zebrina​

Zebrina, also known as Zebra Arborvitae, is notable for its strikingly variegated foliage. The leaves have yellow-striped patterns that create a bright contrast against the deep green background. This variety grows to about 10-15 feet tall and can bring an element of excitement to shrub borders or garden beds.

5. Aurea​

Aurea, or Gold Arborvitae, is distinguished by its golden-yellow foliage that stands out throughout the seasons. While it grows to a similar height as the Emerald Green variety, its eye-catching color makes it a favorable choice for adding brightness to landscapes, especially in shaded areas where it can provide a splash of color.

6. Techny​

The Techny variety is a versatile selection known for its hardy nature and dense growth habit. Typically growing to about 10-20 feet tall, it features a full and bushy appearance, making it a preferred choice for hedges or windbreaks. The Techny Arborvitae is adaptable to a range of climates and soil conditions.

Conclusion​

Cork Arborvitae offers a diverse selection of varieties, each with its unique characteristics suitable for various landscaping needs. When choosing a variety, consider factors such as growth rate, appearance, and environmental adaptability to ensure it fits well within your garden design. Proper care and maintenance will ensure that these beautiful conifers thrive and enhance the beauty of your outdoor space.

Health Benefits​

The Cork Arborvitae, scientifically known as Thuja plicata, is a versatile tree that offers several uses attributed to its health and wellness applications, particularly in traditional practices. Primarily, the tree's foliage is rich in essential oils, which possess antiseptic and anti-inflammatory properties. This makes it popular in herbal remedies and natural therapeutic applications.

Cork Arborvitae has been traditionally used by Indigenous peoples for its medicinal properties. It is believed to help alleviate various ailments, including respiratory issues, by acting as a natural expectorant. The foliage can be brewed into teas or used in infusions, promoting overall respiratory health.

Additionally, the aromatic properties of Cork Arborvitae contribute to its use in aromatherapy. The essential oils extracted from the tree are often used in diffusers to create calming atmospheres and are thought to alleviate anxiety and stress.

Moreover, the durability and natural decay resistance of Cork Arborvitae make it suitable for use as a natural material in constructing wellness-focused spaces, promoting a sense of tranquility and connection to nature. With its holistic properties and environmental benefits, the Cork Arborvitae plays a unique role in health and wellness applications.

Fun Facts​

Fun Facts about Cork Arborvitae (Thuja plicata 'Zebrina')​

  • Unique Variegation: The Cork Arborvitae is known for its striking foliage, featuring vibrant yellow stripes that contrast beautifully with its green background. This eye-catching variegation can brighten up a landscape throughout the seasons.

  • Resilient to Pests: Unlike many other conifer species, Cork Arborvitae has a natural resistance to pests and diseases, making it a low-maintenance choice for gardeners seeking an easy-to-care-for evergreen.

  • Wildlife Friendly: This tree provides excellent habitat for birds and other wildlife, offering shelter and food sources, particularly in its dense, layered foliage. Gardeners can enjoy watching various birds nesting and foraging in its presence.

  • Adaptable Growth Habit: Cork Arborvitae can grow into an impressive height of 10-15 feet, with a spread of about 3-4 feet. Its vertical growth makes it an ideal candidate for tight spaces or as a privacy screen, while its narrow profile allows for versatility in planting schemes.

  • Cultural Significance: The species, Thuja plicata, is commonly known as Western Red Cedar and has been significant to Native American cultures for centuries, being utilized for its wood in crafting canoes, tools, and even ceremonial items.