for the Garden
One of the most iconic of Australian plant groups would undoubtedly be the eucalypts – the ‘gum tree’. There is very little habitat you could visit on this great land where you would not be able to find a specimen growing – from the deserts of central Australia to the cold, high rainfall environment of western Tasmania. For many gardeners, the humble ‘gum’ is often seen as just another large tree towering too high to be safely cultivated in a suburban garden, but if you look further at their diversity, many would be surprised to discover the amazing array of smaller growing eucalypt species that are highly ornamental and well-suited to a home garden.
In this day and age, for gardeners wishing to cultivate and landscape with natives, appropriate species (cultivar and form) choice is a must i.e. species that are suitable for surviving in our harsh, dry, temperate climate, requiring no additional watering. Many of the more ornamental eucalypts naturally occur in dry sites and therefore are able to cope with our Melbournian climate. There are of course many other reasons why one should consider growing eucalypts in their garden when you take into account the variety of features found amongst them including size, form, bark colouration/texture, leaf shape/colour, flower bud shape/colour, flower colour and fruit shape/colour…need I say more? Eucalypts also have much more ‘character’ and ‘personality’ than many other plants – both native and exotic.
There are approximately 900 species of eucalypts (including the genus Angophora and Corymbia) and many of its species are considered ‘small’ trees – that is, being less than 10 m in height. This provides the home gardener with many species to choose from when planning a garden. In addition, many of these smaller growing eucalypts are highly ornamental which adds to their appeal. Is there ever a reason not to plant a eucalypt? If you think yes, then I hope the following information will make you think twice!
One advantage of growing certain species of eucalypts is owed to a unique structural adaptation that some species possess, enabling them to survive harsh environmental conditions such as wild fires – the structure is known as the lignotuber. It develops between the axis of the cotyledons and first few leaf pairs and can become extremely large with age. Often the tuber is not obvious and may lie below ground level; you may be able to notice it on a potted specimen as a visible, potato-like lump at the base. The lignotuber possesses many dormant vegetative buds which allow the plant to regenerate or ‘shoot from the base’ and in doing so, will often develop the distinctive mallee growth habit. Its advantage in cultivation is that if your specimen is growing too large or robust, it can be cut back to near ground level and should not die. Ideally it will reshoot from the tuber and create a multi-stemmed specimen that may eventually have a smaller stature than a single-trunk specimen
Species such as Eucalyptus albida (white-leaved Mallee, WA) and E. latens(Narrow-leaved Red Mallee, WA) (cultivar – Moon Lagoon) have beautiful juvenile foliage and can be grown as hedge-type specimens. By cutting back regularly you can create a bushy, multi-stemmed specimen full of beautiful silver, juvenile foliage. This foliage is popular with the florist trade so you may also be able to sell some of your cuttings and make some extra pocket money! Even if you get lazy with cutting these species back, they will only reach a maximum height of around 3-5 m and would make a beautiful feature specimen with both being quite floriferous. Another sensational species to grow for its stunning juvenile foliage is E. formanii (Die Hardy Mallee). It has extremely thin juvenile leaves with a beautiful silvery-grey colour – at first glance (and even at second) it does not resemble any eucalypt foliage. As a mature specimen it is highly floriferous and its thin adult leaves are often obscured by masses of cream-white flowers. Specimens may reach around 5-10 m.
Eucalyptus erythronema (Flanged White Mallee, WA) is a stunning species to grow if you like bold and ever-changing bark colouration. In season, its bark is rich satiny-red with tones of pink-brown which eventually shed to reveal a powdery white finish. If this isn’t enough, it also puts on a great flower show with flower colours of either yellow or red. It is a medium sized mallee reaching around 2-6 m and can be cut back if necessary. There are two subspecies; erythronema and marginata.
Another lovely group of mallee eucalypts include species with ribbed flower buds; all naturally occur in arid desert areas. E. youngiana (Large-fruited Mallee, WA and SA) has the heaviest flower buds and fruits of any eucalypt and flower displays are spectacular. The huge flowers may either be red or yellow. A closely related species that grows to approximately the same overall height, though often less robust in stature, is E. kingsmillii (Kingsmill’s Mallee, WA) (ssp kingsmillii and ssp alatissima); reaching heights of around 4-10 m. Alternatively, another option would be either E. pachyphylla (Red bud Mallee, Central Aust) or E. sessilis (Finke River Mallee, Central Aust.) which grow to a smaller stature of around 3-5 m. Both have yellow flowers which contrast well with their red-pink operculum. Being all desert species, they require excellent drainage and would prefer a hot, dry, sunny location.
Another brilliant desert dweller is E. pimpiniana (Pimpin Mallee), a rare plant occurring in scattered locations through the Great Victorian Desert (S.A. & W.A). This mallee is more shrub-like and rarely will exceed 2 m in height, though it may spread wider than its height. It often flowers quite prolifically while young and has clusters of pendulous bright yellow (rarely cream) flowers. A stunning small specimen for a hot, well-drained, open, sunny site.
For a different point of interest when landscaping your garden, there are a couple of unusual species that may just be what you were looking for. Both can be described with a few words – sparse, spindly and straggly. Doesn’t sound appealing does it? If you require some structure and height in a garden but don’t want a large canopied specimen or have limited space, then E. sepulcralis (Blue Weeping Gum, WA) and E. desmondensis (Desmond Mallee) may be worth a try. E. desmondensis grows to around 3-5 m, tolerates well-drained heavy sites and has very few leaves. It has beautiful glaucous branches which contrast strikingly with its red-brown flower buds that produce cream or pale yellow flowers. The unrelated E. sepulcralis reaches around 3-8 m in height and has a thin trunk that is usually around 5-6 cm in diameter. This species is commonly known as the weeping gum for good reason, forming a wispy canopy of pendulous branches and produces yellow flowers with glaucous branches and buds. To enhance these two species they would look best if planted in small groups. Alternatively, since they both form lignotubers, you may want to cut them back to form a mallee specimen. Think outside the square with these species and you will surely be rewarded.
This article only includes a very small number of possible species that would be useful and appropriate to grow in a smaller garden, of course there are many more species to choose from and all provide something different to a garden. However, one of the biggest problems isn’t just choosing a species, but finding where to purchase them. Often the best option is to grow your own specimens from seed or find specialist growers. Some of the nurseries that stock a good selection of smaller, ornamental eucalypts are Goldfields Revegetation (Bendigo) and Vaughan’s Native Nursery (Pomonal). Alternatively you are welcome to contact Jason to obtain a current species list or place orders.
Note: The species in this article are linked to photo gallery in Australian National Botanic Gardens (ANBG) website.