Our indigenous species are being destroyed by disease but resistant ‘aliens’ like eucalyptus can safeguard our timber industry and our wildlife
We have been about as successful at keeping pests and diseases out of Ireland as the Gardaí have in preventing the import and sale of illegal drugs
The huge scale of the horticultural imports here almost guarantees that under a leaf or a potting tray somewhere, an insect or a fungus with the capacity to destroy a species will arrive regularly on our shores.
In selecting what to now plant, common sense must prevail — we need to ignore the protests of those who campaign for native species only.
Our natives are few in number, and each year more and more are hit by new diseases.
Our climate is undoubtedly changing, and as temperatures rise and rainfall patterns alter, different pests and diseases have found a home in Ireland.
We need to keep searching for additional tree species that are better suited to this environment and have in-built immunity, rather than just wringing our hands about the death of so many oak, ash, larch, alder and who knows what else.
The arrival of various phytophthora diseases has been devastating, and there are many insects waiting in the wings to cause further havoc.
Fortunately, the natural world is efficient at adapting to changing circumstances, and what are often termed ‘alien’ tree and shrub species now host an astonishing range of diverse flora and fauna.
I will never forget what occurred 20 years ago when I planted a quarter of an acre with pittosporum, an attractive evergreen shrub that is native to New Zealand and is popular for sale to florists.
To my surprise, this ‘alien’ was quickly adopted by many songbirds as a nesting site — so much so that I had to stop harvesting it in spring and early summer as I found that everything from blackbirds to wrens and even a few wood pigeons had set up home throughout the small plantation.
The berries were also popular as a food and as occurs with rowan and other plants and trees, they passed through the birds, and pittosporum started popping up all over the garden.
The same thing occurs here with that lovely evergreen creeper Cissus striata that clings thickly to one wall of my house, which also provides abundant food for birds and bees as well as a popular nesting site.
Like most gardens, mine contains a huge variety of species from all over the world and by trial and error, those that thrive best in the existing soil and conditions are the ones that remain. Plants tell us very quickly if they are not ready to adapt to where they are placed.
In the woodland, it is clear that some trees do not like their location whereas others, such as American red oak, Norway maple, walnut and Spanish chestnut, are proving hardy and resilient.
The trees themselves tell us most of what we need to know.
Birch and alder have shown themselves to be unexpectedly choosy as to where they will prosper — often in sites where the text books would suggest otherwise.
In 2014 we planted eucalyptus as small 20cm ‘plugs’ and most have already reached remarkable heights and girth.
These could well be the ideal trees for short-rotation coppice to produce wood fuel as well as fencing posts and other more valuable construction materials.
It is far too soon to know if frost and/or pests and diseases will eventually hinder progress, but we have to try.
Having trialled a number of eucalyptus species, so far E denticulata has proved to be the most suitable in terms of rapid growth and hardiness. Thinning these recently, we harvested stems of around 20cm DBH (diameter at breast height).
This is an excellent return after just 7/8 years growing and suggests that coppicing them every eight or so years should give us an abundant supply of high-quality, valuable fuel.
E nitens, which is very frost-hardy, also grew well but so rapidly, it had a habit of falling over and requiring staking, as did E glaucescens, so the labour involved in growing them eliminated them from my list.
Eucalyptus is also popular with florists as a long-lasting green filler for floral arrangements — yet another good reason to grow them.
Deer are beginning to become a problem in my woods. I am unsure how to deal with them. All suggestions are welcome.
Joe Barry is a farmer and forester in Co Kildare