Friend or foe? Eucalypts champion defends a misunderstood species

Nicolle has grown the entire collection from seeds he collected in the wild. He is always on the lookout for new species. On a recent drive to Melbourne he allowed time to "stop off at a few places where I haven't collected before".

Eucalypts – any plant relating to the three closely related genera of Eucalyptus (about 800 species), Corymbia (about 100 species) and Angophora (about 12 species) – are everywhere. There are eucalypts that grow in heavy clay soil, rocky outcrops, tropical floodplains and deserts. They can be towering trees or multistemmed shrubs and there are a vast array of barks, leaf types, buds, flowers and fruits.

"Calling a plant a eucalypt and stereotyping it into one group is really unfortunate," Nicolle says. "A lot of general comments are made about eucalypts that don't apply to a lot of the species."

Top of the list has been concern about their flammability after the 2009 bushfires. Some have been arguing that eucalypts – unlike European trees – exacerbate fires because of the oil glands in their leaves and the way that some species shed bark. During a recent panel discussion called Eucalypts – Friend or Foe? the Diggers Club's Clive Blazey explained why he believed that, when used in the wrong places, the eucalypt was a "pretty nasty plant". As well as being particularly flammable, eucalypts provided insufficient shade, were prone to limb drop and outcompeted other desirable plants.

"I don't want you to think I am bigoted against the eucalypt," he says. "I spend most of my spare time in the bush ... it's just about being rational about what goes where."

But Nicolle insists there are eucalypts "for every occasion and need".

"There is a lot of misconception about the eucalypt. Lumping 1000 plants into one is really unfortunate."

Nicolle, who lives in Adelaide and describes himself as a consultant arborist, botanist and ecologist, spends much of his time advising on how eucalypts can be used in the urban environment.

"The stereotype of a eucalypt is a big tree that catches fire or drops branches but over half of all eucalypt species are multistemmed shrubs or mallees. You can manage their size by coppicing them and they should be planted more widely in urban landscapes."

And even some large eucalypts, such as the spotted gum (Corymbia maculata) that can reach 35 metres in cultivation, make "largely stately" trees that, he says, are more drought-tolerant than oaks or elms and are good for fire-prone areas because they have low oil content in their leaves, don't build up much dead material in their crowns and shed bark "cleanly".

Nicolle has outlined the cultivation and uses of 165 eucalypt species in two new companion books, one devoted to taller eucalypts and the other to smaller ones. But the tricky part can be finding nurseries that sell some of the less common species he details. Nicolle wants to change that, which is why he is busy spreading the word.

dn.com.au