|Grow as a houseplant or under heated glass.
|10 to 15C+
|Indoor / Outdoor
|Grow indoors, or outdoors in summer in a sheltered spot
|5 to 10C
|Grow outdoors in summer, and in a heated glasshouse in winter.
|1 to 5C
|Grow outdoors or under glass without risk of frost.
|-5 to 1C
|Hardy in coastal/mild/sheltered areas. Will not tolerate hard/sudden frost. May require winter protection in situ. such as fleece or straw mulch.
|-10 to -5C
|May suffer at altitude, central/northerly locations, harsh winters, cold gardens and when grown in pots.
|-15 to -10C+
|Will survive most severe winters but may be at risk in central/northerly locations and in pots. Top growth may be destroyed but will usually re-grow.
|-20 to -15C
|Will survive severe winter, but may need protection when grown in pots.
|-20C & Colder
|Very Hardy / Hardy
|in the severest European climates.
Originating from S.E. Australia
One of the hardiest eucalypts we can grow in the UK, it also happens to be one of the most stunning. Larger trees have mostly creamy white bark covering the trunk and even smaller branches, making a ghostly and ethereal-looking specimen. Pink and tan coloured strips of older bark peel throughout the season to reveal fresh nearly pure white bark below.
Quickly growing to make a beautiful small tree at a rate of up to 2m per year, it can easily be trimmed to limit it to a large shrub size, or a small tree of around 4 – 5m tall. Pruning is best carried out in late spring, well after late frosts and before the tree starts its vigorous growth in mid-summer. The Mountain Gum’s root system has a swollen form of root below ground called a lignotuber, around the base of the tree, allowing it to regenerate after extreme pruning, even coppicing (cutting all top growth back to ground level), and after very harsh winter conditions. Very cold winter weather will not harm a mature Mountain gum, but younger trees are slightly less hardy.
The crown of this magnificent species is one of the lushest most abundant of all Eucalyptus species, with new leaves emerging in an oval, pink, and bronzy colour and maturing to a blue-green, up to 25 cm long, slender and scimitar-shaped. They have a glaucous, slightly glossy, and reflective surface, making a unique ‘bush light’ around the tree – a subtly refracted, dappled light that shimmers as they flutter in the slightest breeze. The leaves are thicker than most broad-leaved species, having a slightly leathery character. As they blow in the wind they make a calming rustling sound as they flap against each other. Completing the sensorial experience of this species is the aroma of the leaves which have a rich spicy undertone to the usual bright smell. After a hot summer’s day, on a humid evening, it is possible to sit below a Mountain gum and be suffused with its aroma, filling the air as the warmth of the day turns to evening cool.
Pure white flowers are borne in summer on the current season’s stems in clusters of three, looking like miniature sea urchins. Their nectar is hugely attractive to all pollinators. They leave dried seed capsules on the branches that may persist for many seasons. Flowering may be interrupted by different pruning regimes, particularly if it is grown as a mallee, or thicket, where it is coppiced, or forms a hedge. When grown in this way, or as a small tree it makes a fantastic backdrop to Mediterranean-style planting schemes with Cordyline australis, Phormium ‘Black Velvet’, Astelia ‘Red Shadow’, and Astelia ‘Silver Shadow’. These species as well as Yucca filamentosa ‘Colour Guard’, Yucca baccata, and Yucca ‘Bright Star’, all have great tolerance to root competition, so can be planted near all but the largest Eucalyptus specimen.
Hardy and easy to grow in any well-drained soil in full sun, great in coastal climates and exposed positions.
Height and spread after 5 – 6 years if not pruned 8m x 5m
Semi mature height after 10 – 20 years 15m x 10m
Very old trees in the UK have reached 40m tall.