Thuja occidentalis Morgan is a highly decorative evergreen conifer that is prized in Australian gardens for its remarkable seasonal colour changes and neat, oval habit. Unlike many other conifers that remain a static shade of green, Morgan undergoes a dramatic transformation as the weather cools. During the spring and summer, the foliage is a vibrant, fresh lime-green. As the winter chill sets in, the entire plant shifts to a rich, warm copper or plum-bronze tone, providing a much-needed splash of colour during the dormant months.
This cultivar is naturally dwarf and very slow-growing, typically reaching only about 1 metre in height over ten years. Its foliage grows in tight, vertical, fan-like sprays, creating a very dense and formal appearance without the need for constant clipping. Because of its petite size and non-invasive root system, it is a perfect choice for small gardens, rockeries, or formal entrance displays where a low-maintenance structural element is required.
Care Tips
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Position: Thrives in full sun. While it can tolerate very light shade, the best winter colour and the tightest foliage growth are achieved when the plant is in an open, sunny position.
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Climate: Prefers cool to warm temperate climates. It is very frost-hardy and actually requires the cold winter temperatures to trigger its iconic colour change. In extremely hot, arid regions, it may require protection from scorching winds.
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Soil: Requires moist, well-drained soil rich in organic matter. It prefers slightly acidic to neutral soil and does not like to be in a position where the soil bakes hard and dry.
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Watering: Needs regular watering, especially during the first few summers. While it is relatively hardy once established, it does not have high drought tolerance and prefers the soil to remain consistently moist but not waterlogged.
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Fertilising: Apply a balanced, slow-release fertiliser in early spring to support the new season’s growth.
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Pruning: Generally requires no pruning due to its naturally compact and symmetrical shape. If you wish to maintain a very specific size, light tip-pruning can be done in spring.
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Maintenance: Mulching around the base is highly beneficial to keep the roots cool and retain moisture, which helps prevent the foliage from browning out during dry spells.
Landscape Use Thuja Morgan is an exceptional choice for container gardening. It looks beautiful and formal when planted in a Stump pot, particularly when used in pairs to flank a doorway or gate. Its slow growth and colour-changing foliage also make it a great candidate for a Divider Trough, where it can provide a low, decorative hedge that changes with the seasons.
