Growing on a Rock: Ilnacullin Island, Bantry Bay – Mary Hackett

“When you work for a family-owned heritage garden, you learn not to stick with things that aren’t working.” So says Glyn Sherratt head gardener on Ilnacullin or Garinish Island. He’s talking of what he learnt while working with the Cavendish family at Holker Hall in Cumbria. Following over ten years of structural work by the OPW on Ilnacullin, Glyn’s job is now to revitalise the island garden. He is looking back to the original garden imagined by John Annan Bryce and his wife Violet and forward to a space that will accommodate waves of summer visitors while managing changing climatic conditions.

A gate into the walled garden Ilnacullin

In 1910 the Bryce family asked British architect Harold Peto to design a garden for the rocky island they had purchased in Bantry Bay. Peto designed Ilnacullin’s famous Italian or sunken garden with a reflective pool, colonnades, and pavilions set against a backdrop of the Caha mountains. His overall plan for Ilnacullin balanced the classical with wilder, Robinsonian elements including a jungle, a Happy Valley and extensive woodlands. Modern Ilnacullin is not a complete realization of Peto’s concept. The Bryces lost money when the Russian empire collapsed in 1917. Their seven-storey family mansion planned for the Martello Tower headland, the anchor of Peto’s Arts and Crafts scheme, was never built. Without that house, the garden developed rather differently than Peto had envisaged.

Work on the Italian or sunken garden started in 1911. The casita and Medici pavilion suggest the Mediterranean influence for which Peto’s designs are famous. The tilt of their eaves nods to his interest in Asian culture, a feature of the Arts and Crafts movement. Planting however is not the Mediterranean terraces we expect from Peto. Perhaps by the time the garden was ready for planting he had stepped away. Annan Bryce was an enthusiastic plantsman who sourced material in Kew and Mount Usher, from Scottish estates and from other plant collectors. His first plantings failed disastrously. It took a robust shelterbelt of pines and cypress, planted by ‘Mac’ Murdo Mackenzie who arrived as head gardener in 1928, to protect the garden from salt-laden Atlantic gales and allow subtropical plants to thrive. Mac and his successors were professional gardeners rather than botanists. Formal bedding schemes were popular, and Mac’s rose garden was the pride of the island while he gardened there. Glyn now sees lush subtropical species, exotic shapes and striking foliage taking the place of summer bedding. As a garden open to visitors must also have colour, dahlias, salvias, and pelargoniums are also on his planting plan.

The casita on the east side of the sunken garden

Ilnacullin gardens were well maintained under successive OPW head gardeners but upgrading the hard structure of the island had become urgent. “A garden needs forward momentum,” says Chris O’Neill who oversees Derrynane, Fota Arboretum and Ilnacullin for the Office of Public Works. Starting in 2013, walls in the walled garden were recapped and paths excavated from rampaging growth. The ceiling and pillars of the Medici pavilion were repaired. The Connemara marble floor in the casita was restored. The Temple got a new lead roof and the Martello Tower a badly needed lighting system. The Bryce family home was modernised for universal access and conserved. With a warmer climate, greater evaporation is leading to more intense downpours and blocking weather patterns mean weather can be slower to move. Rain is not a significant problem on the rocky island as it drains away quickly. Rising tides however are a different matter. Flood barriers are needed for the buildings closest to the tideline – the boathouse and the café. At the other extreme, water collection tanks are planned and irrigation including energy efficient ways to pump water around the garden is being researched.

The Italian or sunken garden, Ilnacullin

While there will always be structural projects needing attention, focus is now on reimagining the planted environment. Glyn is clear. “The entrance to a spectacular garden like this one should be quite bland. The garden opens out as you walk into the landscape. Each junction should have a glimpse of something to draw you onward. I keep signs and maps to the minimum. The garden will offer glimpses and surprises to pull the visitor on.” On the morning I visit, the one-hundred-year-old wisteria on the Italian terrace is in glorious flower. Planting in the sunken garden includes olearia, hoheria populnea with its bright blue pollen, callistemon and leptospermum. Happy Valley is rich in scented rhododendron and extraordinary tree ferns have emerged triumphant from the pitch-black tangle of the overgrown jungle area.

Unchecked growth is an immediate and urgent concern. When renovating a heritage garden like Ilnacullin, the first step is identification of plant material on the site. Plant lists had lapsed since the 1990s. Glyn spent his first year on the island pulling together every shred of plant records he could find. Then he began to prune. Two years into his project, the original design as interpreted by the Bryce family is re-emerging. Glyn shows me champion trees rescued from invasive griselinia and the walled garden he slashed through with a machete. Murdo Mackenzie’s shelter belt needs reassessment and replanting. Glyn’s to-do list includes exposing the natural stone terraces and outcrops hidden behind a century of exuberant growth, restoring the sight line between the Temple and the Tower, picking key mountain views which can be opened without danger to the garden and propagating some of the largest rhododendrons before repositioning them. Not forgetting reinstating topiary peacocks and sham-fighting the island’s only full-time resident, a ginger tomcat. This, he assures me, is the kind of gardening he enjoys most.

The view from the Temple promontory Ilnacullin

I took the ferry back to Glengariff with a handful of the 75,000 visitors Ilnacullin will welcome this year. The extraordinary Bryce family gave their garden to the nation. Glyn, Chris and their teams steward it magnificently for all of us. Please go visit. And while you are there, make your obeisance to the ginger tom. You are, after all, mere visitors to his kingdom.

Ilnacullin-Garinish Island is open from March to 3 November 2025. Access is by ferry from Glengariff. Bryce House is open to a limited number of visitors except in July and August when the House is closed.
The island has a coffee shop and café, toilet facilities and disabled access. No dogs please.
Ilnacullin-Garinish Island, Bantry Bay, Co Cork. An OPW property