My heart has been pounding more than once this holiday: as I zip-wired through the rainforest, and as I hiked up the steep rocky path of one of the world's largest volcanic plugs. But now, the racing heartbeat has nothing to do with exercise. I am sitting in a parked car on a dirt path. Below me is a cluster of buildings above a brilliant blue Caribbean sea. This is Derek Walcott's St Lucian home and I am plucking up the courage to walk down.

The Nobel laureate is considered the Caribbean's foremost poet and playwright, and has put his island on the literary map in work that explores the post-colonial situation and gives voice to the West Indian people, culture and landscape. Next Saturday is his 80th birthday and he will be playing host to other literary greats including Irish poet Seamus Heaney and African playwright Wole Soyinka. I intend to get a preview of what Walcott is planning for his guests, and his recommendations for what to see and do in St Lucia.

This hilly volcanic island belongs to Walcott in the way Gabriel García Márquez possesses South America or Salman Rushdie's thumbprint is on India. In his 1973 verse autobiography Another Life, he tells of the vocation he felt to "name" St Lucia – this "virginal, unpainted world" that was missing from the history books, where there were "forests of history thickening with amnesia". His birthplace has been the backdrop to many of his works, most notably his 1990 epic poem Omeros, in which he reimagines Homer's Odyssey as the tale of two St Lucian fishermen.

Walcott is wary of journalists and had initially barked at me on the phone. However, when he realises it is his island I want to talk to him about, he becomes an affable host, offering me rum punch and inviting me to join him and his partner Sigrid for a swim and lunch.

Later, we pack deckchairs into the boot of a jeep and Walcott climbs into the back, grumbling as his partner Sigrid drives over rough ground on a shortcut to the beach. "Derek's son Peter calls this bit Serengeti," she jokes, and there is a whiff of Africa about the place: a couple of horses stand like wary antelope under a calabash tree. Many of the roads would have been like this when Walcott was growing up.

"We didn't travel much," he says. "We went to Soufrière, where the Pitons [the island's twin peaks] are, but the road from the capital, Castries, was torturous, so we went by boat. It's a terrific journey." His grey blue eyes dance at the thought. "That's what I'll be doing with Wole and Seamus. It's a hell of a trip, coming in under the Pitons."

Walcott also plans to take his guests to a favourite restaurant, Dasheene at the Ladera resort above Soufrière: "I know the chef there, and the view's incredible."

"It's my favourite place," says Sigrid. "We stayed there a few nights when Derek was working on the film version of his play Ti-Jean and His Brothers."

I go there the following night. Chef Orlando Satchell, British of Caribbean parentage, cooks a menu that combines fresh produce, traditional recipes and international know-how. Dishes include fried green tomato and plantain tart with goat cheese salad and guava balsamic, and chicken stuffed with plantain mousse served with a sweet potato dauphinoise.

I stay a night at this retreat, where the rooms have just three walls, and each has its own plunge pool, a playground for bugs and birds, which you can shoo with your complimentary water pistol if they get too close to your biscuits. From here, you can take a guided hike up Gros Piton, which Walcott often refers to in his work ("In the mist of the sea there is a horned island/with deep green harbours"). It is a steep climb, and will make you pant, but the views over the lush rainforest interior with its white sand-fringed edges are worth the effort.

Walcott now lives just outside the northern town of Gros Islet, where he set much of Omeros. "They have the jump-up on a Friday night," Sigrid says as we drive. "It's a big street party, with stalls of barbecued food and lots of music and dancing." I've been to a similar Saturday night in Dennery, on the east coast, where Walcott used to visit an aunt as a boy. I remark on the suggestive dancing. "Of course the dances are sexual," says Walcott. "That's what's great about them – but there is wit in the movement: it is a parody of the act."

In daylight it's hard to imagine such raucous partying; the village seems a world away from the tourist developments at nearby Rodney Bay. Men swig from bottles of Piton beer on the first-floor verandas of wooden buildings that tell of the island's colonial past. The French claimed St Lucia in 1635, with the British hot on their heels. The island changed hands between the two powers 14 times before the British finally wrested control in 1814, running it as a colony until it won independence in 1979. Walcott's house overlooks Pigeon Island, an outcrop that was once a fortress and is now a national park. He stages a harrowing scene in Omeros here, imagining slave ancestors building the fort for the British Admiral Rodney, and recommends a visit.

Any other suggestions? "The riding here is great. Have you been riding?"

There are stables in Gros Islet, and a couple of days later I take a gentle trek to a little beach at Cas en Bas. Here, the guide removes the saddle and coaxes my horse into the sea. I feel like I'm in a 70s B-movie, sitting in my bikini on the damp flank of a black horse in an eau de nil sea. I can't quite imagine Heaney and Soyinka riding bareback with Walcott, but you never know.

He recommends the Royal by Rex at Rodney Bay. Walcott likes it because it is one of the few hotels that isn't all-inclusive, allowing him to dine at his favourite places on what he terms "restaurant row", just behind the hotel.

"There's a very good Chinese – Memories of Hong Kong – and a fine Indian."

Walcott believes all-inclusive holidays are bad for local businesses, and this isn't the only gripe he has with the tourist industry: "All the building that is going up is absentee-ownership. It's another plantation culture."

Today, we are having lunch at home. Walcott sits at the wooden table on the veranda with a big bowl of mashed avocado and starts mixing in capers and cassava flour. It's his own recipe. Sigrid brings out spiced beef stew, braised purple cabbage, boiled breadfruit, rice and peas – and it's all delicious.

(This is my second taste of traditional island food My first was at a gem of a restaurant near Laborie in the south of the island called Debbie's Place, where with every main course Debbie brings dish after dish of side orders. Go for lunch, preferably having skipped dinner the night before, and you can enjoy the backyard atmosphere all afternoon.)

"Isn't this just marvellous?" Walcott says suddenly. And I look out at a scene that might have been enhanced by Photoshop: the blues of pool, sea and sky, the whites of sun-loungers, egrets and scudding clouds, all framed by the varying greens of lawn, palms and the "twin-humped promontory" of Pigeon Island.

It's easy to understand why St Lucia is the palette Walcott always returns to.

Essentials

British Airways (ba.com) and Virgin Atlantic (virgin-atlantic.com) fly to St Lucia from £510 return. Virgin Holidays (virginholidays.co.uk) offers a week at the Royal by Rex hotel with flights for £869.

Dasheene restaurant is at the Ladera Resort (ladera.com). International Riding Stables in Gros Islet offers fully insured riding for all levels (00 758 452 8139). Book a table at Debbie's Place on 00 758 455 1625.