Sweet sap and size bless a hearty tree

I HAD to cut down another tree that had got too big for its boots the other day.

This one was a tall eucalyptus.

There are around 500 different species of eucalyptus, all native to Australia, but only a handful of them are hardy enough to survive in Ireland. This one was a Eucalyptus gunnii, also known as the cider gum.

They are the fastest growing trees in Ireland, capable of putting on well over a metre a year in milder parts of the country with suitable soil conditions. They will also survive in colder places, though they won’t grow quite as fast – I’ve seen them flourishing at considerable altitudes in the Wicklow mountains.

Their hardiness comes from the fact that they are native to the central plateau of Tasmania, which apparently has a climate quite similar to Ireland’s. The speed at which they grow is amazing. I reckon the one I cut down was well over 20 metres in height – the tallest tree I’ve ever felled – and yet it only seems a few years since I planted it as a one metre tall sapling. I have a couple of others that I planted more recently

and they’re also reaching for the sky, with trunk diameters of about 35 centimetres. Australians call these gum trees and this species has a sweet sap that was tapped in the past in the same way that sugar maples are. The sap was fermented to make an alcoholic drink, which is where it gets the name “cider gum”. Apparently there is some research going on at present into possible new uses for this sap.

One of the reasons they get so tall, so fast, is that they’re evergreens and will continue to grow for 12 months a year if conditions are right. Most tree species in this country only grow for a few weeks in the year, typically in late spring.

This also means that they have no dormant period, and it’s usually better to fell a tree when it’s dormant. Now I’m cutting up the one I felled and splitting the logs for the fire. It makes excellent firewood.

But splitting fresh eucalyptus logs is like walking into a chemist’s shop – you are surrounded by the pleasant, antiseptic scent of nasal inhalers. They coppice well, which makes them an interesting option to grow as a timber crop. But they would normally be felled younger and smaller than mine if coppicing is intended so I’ll be interested to see if any new shoots appear from the stump of this one. The young leaves, if any appear, are quite different to the mature ones – nearly round and a pale bluish colour while the mature ones are long, like large willow leaves, and dark green.

They also have a tendency to shed their bark while they’re growing, often in rather untidy flakes and strings. This is a protection against bush fires – apparently the loose bark goes up in flames but the tree beneath survives.

Different species of eucalyptus can be hard to tell apart. Another similar species that grows in Ireland is the blue gum or Eucalyptus globulus. But if you have a small to medium sized garden and find these tall and fast growing species a bit intimidating you should look out for the snow gum. This small species from the high mountains of Victoria and New South Wales is attractive and very hardy. Both the bark and the leaves are colourful and the trunk has a tendency to become crooked.

It has recently been re-classified but will probably be labelled by the nursery under the old name of Eucalyptus niphophila. The correct new name is Eucalyptus pauciflora ssp. niphophila.

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