Which Thuja is Best for Hedging? Your Ultimate Guide to Thuja Varieties for a Perfect Privacy Screen

Choosing the Best Thuja for Your Hedge

When it comes to creating a lush, private, and beautiful hedge, Thuja trees, also known as Arborvitae, are a top choice for many American homeowners. Their dense evergreen foliage provides year-round screening, and with the right variety, they can be remarkably low-maintenance. But with so many Thuja options available, the question arises: Which Thuja is best for hedging? This article will guide you through the most popular and effective Thuja varieties for creating your ideal hedge, detailing their characteristics, growth habits, and ideal uses.

Understanding Thuja Varieties for Hedging

Thuja is a genus of coniferous trees in the cypress family. They are native to North America and East Asia and are prized for their scale-like leaves, conical or columnar shapes, and tolerance to a range of conditions. For hedging purposes, we primarily focus on species and cultivars that offer dense growth, a good growth rate, and a desirable mature size and shape.

The Top Thuja Choices for Hedging:

• Thuja occidentalis (Eastern Arborvitae): This is the most common and widely adapted species in North America. It's a hardy and versatile option with numerous cultivars suitable for hedging.
  • 'Smaragd' (Emerald Green Arborvitae):

    This is arguably the most popular Thuja cultivar for hedging in the United States. Its key advantages include its beautiful, vibrant emerald-green foliage that retains its color throughout the winter, even in colder climates. 'Smaragd' grows in a naturally narrow, pyramidal shape, which means it requires minimal pruning to maintain a formal hedge. It typically grows to a height of 15-20 feet and a width of 3-4 feet, making it ideal for screening without taking up too much yard space. Its slow to moderate growth rate also means less frequent trimming than faster-growing options. It's excellent for defining property lines, creating privacy screens, or as a decorative accent.

  • 'Green Giant' (Thuja plicata x standishii 'Green Giant'):

    As the name suggests, 'Green Giant' is a vigorous grower and a fantastic choice for a fast-growing, tall privacy hedge. This hybrid is a cross between Western Red Cedar (Thuja plicata) and Japanese Arborvitae (Thuja standishii). It boasts a rich green, slightly bronzy-green foliage that holds its color well in winter. 'Green Giant' can reach impressive heights of 50-60 feet or more, with a mature width of 12-18 feet, though it can be pruned to maintain a desired size. Its rapid growth rate (often 3-5 feet per year under ideal conditions) makes it ideal for quickly establishing a dense screen. It's perfect for blocking out unsightly views, reducing noise pollution, and creating a formidable windbreak. However, its larger mature size means it requires more space than 'Smaragd'.

  • 'Holmstrup':

    'Holmstrup' is another excellent 'Smaragd'-like cultivar, offering a dense, conical form and rich green foliage. It's a bit more compact than 'Smaragd', typically reaching a mature height of 10-15 feet and a width of 3-4 feet. It's known for its exceptional cold hardiness and resistance to deer browsing, which can be a significant advantage in many regions. Like 'Smaragd', it requires very little pruning to maintain its shape, making it a low-maintenance hedging solution.

  • 'Degroot's Spire':

    For a very narrow and columnar hedge, 'Degroot's Spire' is an outstanding choice. It grows with a tight, upright form, reaching a height of 15-20 feet but only spreading about 2-3 feet wide. Its foliage is a dark green and has a slightly twisted, attractive texture. This cultivar is perfect for tight spaces, foundation plantings, or creating vertical accents within a landscape. Its dense growth provides excellent screening in a slender package.

• Thuja plicata (Western Red Cedar): While often grown as large specimen trees, some cultivars of Western Red Cedar are also suitable for hedging, particularly if a taller, more substantial screen is desired.
  • 'Excelsa' (Vigilant Arborvitae):

    'Excelsa' is a very fast-growing and adaptable cultivar of Thuja plicata. It forms a dense, pyramidal to columnar tree that can reach heights of 30-40 feet or more. Its foliage is a deep green and retains its color year-round. 'Excelsa' is a good option for a taller, more robust hedge and can tolerate a variety of soil conditions. However, it will eventually spread wider than cultivars like 'Smaragd' or 'Holmstrup', so more space is needed.

Factors to Consider When Choosing Your Thuja Hedge:

When making your final decision, consider the following:

• Mature Size: How tall and wide do you want your hedge to be? Ensure you have adequate space for the mature size of the chosen Thuja.
• Growth Rate: Do you need a fast screen, or are you willing to wait for slower-growing varieties?
• Foliage Color: Most Thuja have green foliage, but some offer shades of green, blue-green, or even bronze in winter.
• Maintenance: Most Thuja are low-maintenance, but some require more frequent pruning to maintain a formal shape.
• Climate and Soil Conditions: While Thuja are generally hardy, research the specific needs of the cultivar for your USDA hardiness zone and soil type.
• Pest and Disease Resistance: Some cultivars are more resistant to common pests like bagworms or spider mites.
• Deer Resistance: If deer are a problem in your area, some Thuja varieties are more resistant than others. 'Holmstrup' and 'Smaragd' are often cited as having better deer resistance.

Planting and Care for Your Thuja Hedge:

Once you've selected the perfect Thuja, proper planting and care will ensure its success:

1. Site Selection: Thuja prefer full sun to partial shade. They also require well-drained soil. Avoid planting in areas where water stands after rain.
2. Spacing: Space your plants according to their mature width to allow for optimal growth and density. For most hedging, planting them 2-4 feet apart on center is common, depending on the cultivar.
3. Watering: Water regularly, especially during the first year after planting, to help establish a strong root system. Once established, they are moderately drought-tolerant but benefit from watering during prolonged dry spells.
4. Pruning: Prune Thuja in late spring or early summer to shape the hedge and encourage dense growth. Avoid cutting back into old wood, as Thuja do not readily regrow from it. For informal hedges, pruning may be minimal. For formal hedges, regular shaping is necessary.
5. Mulching: Apply a layer of mulch around the base of the plants to retain moisture, suppress weeds, and regulate soil temperature.

By understanding the characteristics of different Thuja varieties and considering your specific landscaping needs, you can confidently choose the best Thuja for hedging and create a beautiful, functional, and long-lasting privacy screen for your home.

Frequently Asked Questions (FAQ)

How far apart should I plant Thuja for a hedge?

The spacing for Thuja hedges depends on the specific cultivar and how quickly you want the plants to fill in and create a solid screen. For most hedging varieties like 'Smaragd' or 'Holmstrup', planting them 2 to 3 feet apart on center is a good starting point. For faster-growing varieties like 'Green Giant', you might space them 3 to 5 feet apart, as they will fill in more rapidly. Always check the plant tag for recommended spacing for the specific variety you purchase.

Why is my Thuja hedge not growing as fast as I expected?

Several factors can influence Thuja growth rate. These include insufficient sunlight (they prefer full sun to partial shade), poor soil drainage, lack of consistent watering (especially during establishment), or competition from weeds or turfgrass. Sometimes, the natural growth rate of the specific cultivar plays a role; some varieties are naturally slower growers than others.

How tall can a Thuja hedge get?

The mature height of a Thuja hedge can vary significantly by cultivar. Varieties like 'Smaragd' and 'Holmstrup' typically reach 10-20 feet, while 'Green Giant' and 'Excelsa' can grow much taller, often exceeding 30-50 feet if left unpruned. The ultimate height is also influenced by pruning practices. Regular pruning can maintain a hedge at a desired, more manageable height.

When is the best time to prune a Thuja hedge?

The best time to prune Thuja for shaping and to encourage dense growth is in late spring or early summer, after the main flush of new growth has occurred. You can also perform light shaping in late summer or early fall. It's crucial to avoid cutting back into old, woody sections of the branches, as Thuja do not readily regrow from bare wood. Always aim to prune just behind the green foliage.