Plant Profile and Landscaping Uses
Thuja are a group of coniferous plants with only 5 species in the genus however many more cultivars.
Thuja occidentalis smaragd is the most popular species for adding a structured formal look to any landscaped area.
These slow growing cone shaped evergreen conifers are great screening plants growing to 6m over time depending on species and conditions.
Tis is a plant that prefers full sun where it will grow with a nice dense habit they will grow in part shade, however foliage tends to be a little less dense.
Foliage turns to a bronze / green in colder areas during winter.
How to Grow Thuja occidentalis smaragd – Basic Care
- Full sun to part shade
- Grows well in colder climates and will cope with dry summers after it is well established.
- Good drainage is essential
- Mulch to retain moisture
How To Plant
- Plant in well-drained, acidic to neutral soil.
- Choose a location with full to partial sun exposure for the best growth.
- Space plants 3-5 feet apart if planting for hedging or privacy screens.
- Dig a hole that is slightly wider and the same depth as the root ball.
- Place the plant in the hole and backfill with soil, gently firming it around the roots.
General Care
- Thuja occidentalis is relatively low-maintenance once established.
- Watch for pest infestations, such as aphids or scale insects.
- Mulch around the base to retain moisture and regulate soil temperature.
Pruning
Can be pruned to maintain shape and size. Best pruned in early spring to give new growth a chance to harden off before summer. Fertilize and water after pruning
- Light pruning can be done in spring or late summer to maintain shape.
- Avoid heavy pruning, as it may harm the tree’s natural conical shape.
- Remove dead, damaged, or diseased branches throughout the year.
- Always sterilise saws and other pruning equipment before use.
Landscaping Uses
Use the plant as a tall evergreen hedge.
Space at around 1m for a dense hedge in landscaping applications. When planted in shade the growth habit will be more open than if planted in full sun.
Also useful as a feature plant, or punctuation mark in landscape design.
The common name of for Thuja occidentalis smaragd comes from the dutch word smaragd, which means emerald.
Climate Tolerance
Climate Zones
USDA Zones 3-7 (tolerates cold winters, but not extreme heat).
Adaptable to a wide range of temperate climates, including parts of Australia, the UK, and the United States.
Frost Tolerance:
Very frost-tolerant, can survive temperatures as low as -40°F (-40°C) in mature trees.
Drought Tolerance:
Moderate drought tolerance once established, but young plants require consistent moisture to establish strong roots.
Summary information
- Botanical name – Thuja occidentalis smaragd
- Common Name – Emerald Green Cedar.
- Height – Around 4 – 7 metres
- Spread – From 1 – 2.5 Metres
- Growth rate – Slow to moderate.
- Soil – Tolerant of most soil types, well drained is important.
- Position – Full sun.
- Growth habit – Upright and conical.
- Foliage color – Emerald Green
Other Thuja occidentalis Varieties
Low growing Thuga occidentalis
- T. occidentalis ‘dumosa’ – small rounded bushy plant 80cm.
- T. occidentalis ‘filiformis’ – Long tread like foliage in a plant that will reach around 2m.
- T. occidentalis ‘teddy’ – Blue green foliage in a tight rounded ball shaped shrub to 60cm.
- T. occidentalis ‘Blue Cone’ – Upright oval shape to 1.5m
Medium growing Thuja occidentalis
- T. occidentalis ‘ de Groots spire’ – Slow growing upright form to around 2 – 3 m.
- T. occidentalis ‘Smaragd’ – Probably the most widely grown conifer, will reach 2.5 m in 10 years, however will eventually grow taller. Easily pruned and grows well in containers.
- T. occidentalis ‘Fastigiata’ – Upright form reaching 3 m in 10 – 15 years.
Thuja Species
Three species are from Asia
- T. koraiensis or Korean thuja
- T. standishii orJapanese thuja
- T. sutchuenensis or Sichuan thuja
Two Species come from North America
- T. occidentalis also known as the Eastern arborvitae or Northern White Cedar
- T. plicata or Western red cedar is widely spread from Alaska to California also known as the Giant Life Tree.
•THUJA occidentalis •THUJA orientalis •THUJA plicata
Available from the following growers
111 Stanhope Road Theresa Park NSW 2570
Offering a variety of sun hardy Australian natives and exotic trees, shrubs, groundcover's and perennials from semi advanced through to super advanced and semi-mature stock.
www.downesnursery.com.au
55 McDougal Rd Neerim South Victoria 3831 PH: (03) 56281507
Advanced ornamental trees and garden designs and concept plans. Direct to your property combined with specialist knowledge and outstanding service.
www.blericktreefarm.com.au
email ask@plantmark.com.au
One of Australia's largest wholesale trade nurseries. Over 30,000 species available, tubestock to advanced trees, an almost unlimited choice of plants.
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