Wednesday, March 20, 2024

Let's bust some myths about eucalypts in urban areas

‘Myth’ – a widely held but false belief or idea.

Myth 1 – “Eucalypts are too big for urban areas”

This myth probably originated some years ago when there was increased interest in planting eucalypts in parks, reserves and back yards but little attention was paid to species selection. Yes, of course, SOME eucalypts are too big for back yards and some public spaces. So are some pines and some oaks and some ….

Nearly one half of all 800-odd eucalypt species however are mallees or shrubs that grow no more than 10 metres – some only 2 or 3 metres.

(Image of mallee eucalypts in a garden)

And, it matters where you plant them. You wouldn’t or shouldn’t plant a Mountain Grey Gum within 20 metres of your house. Equally, you wouldn’t or shouldn’t build your house within 20 metres of a mature Mountain Grey Gum. That just does not make any sense at all.

There are plenty of open spaces in most urban areas where the majesty of a mature Mountain Grey Gum can be safely appreciated.

Myth 2 – “Eucalypts are prone to dropping their branches”

A few are, most are not. A large, fast-growing tree of any species will sometimes shed a branch, especially if the branch is heavily laden or disproportionally long.

Climatic conditions – heavy rain, humidity, drought, high winds – can cause ANY tree to shed its branches. Disease can be a reason for a tree to drop a limb. A healthy tree is far less likely to shed its branches.

Eucalypts that are known for dropping branches unexpectedly include; Sugar Gums, some Red Gums, Manna Gums and Yellow Box.

Other species that have a reputation for shedding their limbs include; oak, Liquidamber, pear, pine and ash.

Most trees in Australia are eucalypts, so most sudden limb drop in Australia is going to be from a eucalypt. The term ‘widow-maker’ was derived in the days of early settlers clearing their land – land covered in eucalypts and not much else. Records from other countries suggest that ‘widow-making’ took place during early settlement as well – but the trees were not eucalypts.

Myth 3 – “Eucalypts with borers, termites or mistletoe should be removed”

Many century-old eucalypts can be host to all three and the tree will continue to survive for another century or two. Borers, termites and mistletoe should be viewed as part of the biodiversity of the tree. Termites for example, eat the dead heartwood of the tree and have little impact on the living sapwood and cambium layers. In this way, they create hollows within the tree which are vital for much of our native wildlife.

(Image of large, stand-alone eucalypt biodiversity hotspot)

Mistletoe presents little problem to any healthy tree, eucalypt or otherwise. Mistletoe may impact a tree which is already under additional stress from other causes; dieback, drought, root zone disturbance, etc.

Myth 4 – “Eucalypt roots are invasive”

Not really. They are opportunistic like the roots of ANY tree and will seek sources of air, water and nutrient, just like any plant does for its survival. Eucalypts generally have shallow root systems. Even some of the tallest, biggest gums may have the bulk of their roots not much more than 50cm below the surface. Finer roots might go deeper in the search of water.

Before worrying about eucalypt roots invading your garden, keep an eye out for; Camphor Laural, fig species, willows, Illawarra Flame Tree, casuarinas, Jacaranda and Plane Trees. All are much more of a worry for root invasion than any eucalypts.

Eucalypts encapsulate so much about Australia. They serve so many functions and there is a eucalypt for every home garden, street or park situation. Eucalypts are our urban evergreen canopy.

(Here’s a link to a series of videos on how to select, grow and maintain suitableeucalypts in the home garden by Eucalypt Australia and Royal Botanic Gardens Victoria)

 

 

Sunday, March 17, 2024

Eucalypts in urban spaces

Eucalypts play a vital role in all Australia’s rural ecosystems and have done so for millennia. It is now recognised that their role in urban situations is becoming vital too.

Main South Rd Drouin

There are some issues with this. Conflicts of emotions and opinions arise when trying to reconcile a large, old, majestic, historic tree in an urban location with water-seeking roots, dropping limbs, ‘messy’ bark and ‘annoying’ wildlife.

Australia is a large country and has one of the lowest population densities in the world. We also have a very high urbanisation rate of more than 80%. The evidence is very clear that our urban areas are in dire need of more vegetation to provide a connection with nature, lower the urban heat island effect, clean the air, lower the water table, improve our health, provide habitat – and much more.

While exotic species are capable of doing some of this, it is the eucalypts that are best. Eucalypts are adapted to our climate and our soils – they have been here for thousands of years.

‘Gum’ trees play a significant role in the human psyche of most Australians. During World War 1, families would send gum leaves in their letters to those at the front. Nurses wore gum leaves pinned to their capes and it is said that returning soldiers could smell the eucalyptus before land was sighted.

Eucalypts retain their leaves throughout the year: they provide year-round shade and year-round air-cleaning.

In urban zones, wildlife often rely completely on the presence of eucalypts. They provide food, shelter, refuge, breeding sites, habitat for invertebrates (food for other animals), mistletoe, fungi and micro-organisms in the root zones.

In urban areas, old eucs particularly are especially valuable. And yet, as a eucalypt ages, it is often more readily targeted for removal – it has become ‘dangerous’, or, “It isn’t beautiful anymore, we’ll remove it and replace it with something more attractive for our development”. A well-trained arborist knows that old eucs, even dead ones, are as valuable for biodiversity as younger trees are. Also, good arborists appreciate the threshold of acceptable risk and that removal is not always the best answer.

Equally valuable

Maybe the answer lies in the development of ‘designer eucalypts’ – for another day.

Don’t forget to vote for your favourite Drouin eucalypt: Settlement Giant in Settlement Rd, Grandfather Tree in Civic Park, Railway Giant in Albert Rd, Old Swimming Hole Giant in Lampard Rd or the Ficifolia corridor in Princes Way. Just send your vote to drouinsfavouritetree@gmail.com Winner will be announced on National Eucalypt Day at Alex Goudie Park, 23rd March, 10am.

 

 

 

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Strzelecki Gum

In 1992, Eucalyptus strzeleckii was identified and named in honour of Paul Strzelecki, an early explorer of Gippsland. Strzelecki Gums are endemic to a small part of West and South Gippsland where they tend to grow in deep fertile soils.

Because of its limited distribution, Eucalyptus strzeleckii is listed as Vulnerable under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999 and as Critically Endangered in the Victorian Flora and Fauna Guarantee Act 1988. In both acts, the major threats to this tree include its limited geographic distribution, fragmentation, grazing and trampling by stock, habitat loss, roadworks and loss of genetic diversity.

Strzelecki Gums generally grow straight and tall - the best specimens seem to grow where their root zones get some periodic inundation. Their trunks can have rough bark to varying heights after which it is smooth and shreds in ribbons revealing grey, white, red, green and brown mottling.

The leaves of the Strzelecki Gum are generally oval to lance shaped and often have wavy edges. New leaves have a grey-blue appearance giving the tips a waxy look. Crushed leaves have a strong eucalyptus smell because of the concentration of oil glands.


McNeilly Park in Jackson Dr Drouin is a great place to see both mature and young Strzelecki Gums. The ‘McNeilly Giant’ in the south west corner, although damaged in a recent wind storm, still dominates the skyline. 


On the east bank of the back lake, a natural-recruitment patch of young strzeleckii is standing tall and straight.


You can vote for Drouin’s favourite tree by emailing drouinsfavouritetree@gmail.com The winning tree will be announced on National Eucalypt Day, Saturday 23rd March, Alex Goudie Reserve, 10am. Come and meet some of Drouin’s dedicated tree huggers – walks and talks, door prizes, plantings, etc.