'These fronded beasts from Australia are 100 years old and several metres high - you'd think twice about passing through them at night.' Jane Powers in tree-fern paradise
We don't have a tree fern in this garden, and we never will. It's not that I don't like these frondy antipodean giants. On the contrary, I think they are among the most beautiful of green things. In the right place, that is. Which is why we will never have one in our completely unsuitable garden. During most of the year it is as dry as the Mediterranean, and trying to grow a tree fern here would be like raising ducks without a pond. Because tree ferns - like ducks - have an affinity for moisture. Of course, there's nothing to stop you growing a tree fern in a dry garden, but the water that it needs for its survival has to come from somewhere, and that means from you.
If your patch is parched, you must water a tree fern daily during the growing season - especially in the first year or two when it is establishing. And you must endeavour to keep the trunk damp during droughty weather, because the dark-brown hairy pillar is, in fact, a massive rhizome covered with roots - and it is these roots that crave moisture.
It is worth remembering that the most common tree fern, Dicksonia antarctica, comes from the forests of Australia and Tasmania. It is an understorey plant, thriving in the dappled shade of tall eucalyptus. In areas where there is less than a metre of rainfall per year, it lives in damp gullies, on the margins of watercourses, sometimes with its feet right in the water.
I'm going on about this, because I've just been on holidays, where I visited the happiest tree ferns I've ever seen. After witnessing this sight, I feel it's almost a cruelty to expect these dignified forest-dwellers to put up with the completely unnatural state of being a trophy plant on someone's patio. (Television garden makeovers have a lot to answer for when it comes to creating a climate for tree fern abuse.)
The holiday with the happy tree ferns wasn't Down Under. It was down south, in Cork and Kerry. There, in Derreen garden in Lauragh, Co Kerry (halfway along the upper flank of the Beara Peninsula), live some of the best-adjusted tree ferns on this side of the world. The 80-acre property is nicely sheltered on the edge of Kilmakilloge Harbour, a small inlet bitten out of the side of the Kenmare River estuary. In the famously soft Kerry climate, the garden is washed by around two metres of rainfall a year, and rarely exposed to frost.
It is tree-fern heaven. Colonies of Dicksonia antarctica populate the woodland, spreading their great, green ostrich-plume fans luxuriantly under a canopy of taller trees: oaks, American and Asian conifers, rhododendrons, and - appropriately - eucalyptus. These fronded beasts from Australia are 100 years old and several metres high. They have a magical presence, eerie and beautiful: you'd think twice about passing through them at night. Even in the green-filtered light of day, their spirit is powerful.
Moss has clothed their trunks in a velvety, moisture-retentive fabric, while here and there, opportunistic seedlings of ivy and other plants have seeded in the moist creases. And the ferns themselves have multiplied over the decades, dropping their spores onto the congenial woodland floor, where they have germinated and produced numerous new fernlings.
The hoary old dicksonias at Derreen were planted at the beginning of the 20th century by the fifth Marquess of Lansdowne, who inherited the Kerry property in 1866, and who made it his summer home (when not living abroad in Canada where he was Governor General, and in India, where he was Viceroy). He was a keen plant collector and gardener, turning what had been a bare and rocky acreage into a lush, and - in parts - subtropical woodland.
In springtime, the rhododendrons - including many enormous specimens of R. arboreum - light up the acreage with their candy-coloured blooms. And when not in flower, the large-foliaged kinds, such as R. sinogrande and R. falconeri, lend a jungly air to the place, with their great paddles of leaves. Fat groves of bamboos, self-seeded myrtles and Gaultheria, and monumental conifers add to the exoticism.
The scenery's not bad either, with views across the waters of Kilmakilloge Harbour to the Caha mountains beyond. Or, if you're energetic, a march under the arch of the fallen Cryptomeria and up to the Knockatee seat will give you a vista of the mountain of the same name, seen across the top of a rhododendron wood.
Yet, for me, the glory of this garden is its tree ferns. And I'd urge anyone who is contemplating growing their own, to pay a visit to see the happiest dicksonias in Ireland.
Derreen Gardens, Lauragh, Killarney, Co Kerry, 064-83588. Open 10am-6pm daily. Adults: €6, children: € 3.
DIARY DATE: September 30th to October 2nd, at Dublin Castle: the annual Northern Ireland Heritage Gardens Committee conference. Speakers on this year's theme, "Early formal gardens and gardening", include Terence Reeves-Smyth, David Jacques, Sarah Couch, Finola Reid, John Sales, Brian Dix, Belinda Jupp and others. The weekend ends with a visit to Áras an Uachtaráin. Conference fee €210 or €300 (the latter includes lunches, dinner and other extras). Contact Belinda Jupp at 42 Osborne Park, Belfast BT9 6JN; belindajupp@lineone.net.