The sometimes-smelly tree that might be more useful than you think

But the contentious tree plays a more important role in our urban streets than you might think.

Managing director of Speciality Trees and nursery expert Hamish Mitchell said that while the ornamental pear might have a springtime odour, it was only for a couple of weeks and, for the rest of the year, it was a tough and reliable urban tree.

“I have put these trees into churches for people that are getting married at that time of year. And it’s just occasionally they have an offensive smell,” he said.

“They’re attractive for 50 weeks of the year, but for two weeks they’re attractive, but they just don’t smell very nice.”

The callery pear — known also by its scientific name, Pyrus calleryana — was introduced from East Asia for its advantages as an urban tree.

While it is illegal to grow, sell or plant the callery pear in multiple US states due to its highly invasive behaviour, the tree is not listed as a weed in Victoria.

And the reason behind the heady odour?

Mr Mitchell said it was all about attracting pollination.

“They’ve evolved to attract insects, or birds, to the flowers to pollinate them,” he said.

There are up to six different cultivars of the callery pear, including the Bradford, Cleveland Select and Aristocrat.

“One of the problems with streetscapes is you’ve got compact soils and very poor growing conditions,” Mr Mitchell said.

“(With the callery pear) we get the flowers which are attractive, they go to leaf very quickly, and it’s a very attractive leaf that hangs on during the summer and they’ll cope with the very hot conditions in northern Victoria.”

Moreover, the callery pear may play an important part in the armoury to keep urban streets cool under climate change.

“Climate change is a massive issue that we’re all going to have to deal with,” Mr Mitchell said.

“We really need to get to that 30 to 35 per cent canopy cover to reduce heat in urban areas.”