The formidable beauty of Mehrangarh Fort is now familiar to millions around the world thanks to its role in the latest Batman movie, The Dark Knight Rises. It has towered over the Indian city of Jodhpur for 500 years, inspiring the atmosphere of the city - at least that is how it has seemed.

Walking through a new garden at the fort, the first in India devoted to indigenous desert plants, makes you think again, and realise it's the landscape that has dictated the character of this mighty citadel. Here, the land is brown, arid and rocky, but in the short winters and rainy seasons, even the most brittle, thorny plants manage to muscle up to produce flowers of incredible delicacy and colour.

Seeing a desert flower, just two slim purple petals and a needle-thin stamen, in this harsh terrain only amplifies its ethereal quality. But for the team who created the Rao Jodha Desert Rock Park, which opened in February, the process was far from unearthly.

It took project director and park curator Pradip Krishen, his stoneworkers and planters six years to transform the unruly ravine and hilltop within the grounds of the fort into the 70-hectare desert garden. Krishen planted only flora native to the rocky parts of the Thar Desert, which covers much of west Rajasthan state. Learning to grow them took years of trial and error, detailed records and a great deal of patience.

Clearing the land on which the garden now sits involved a whole new set of problems. It was covered with an invasive species that is almost impossible to eradicate, Prosopis juliflora, known as baavlia, "the crazy one", in the local dialect of Marwari.

Baavlia seems to require no water or nutrients and it secretes toxic alkaloids around its roots to discourage anything else from growing nearby. It is madly successful. Even the story of its arrival here from Central America sounds crazy. It was introduced to huge swathes of land around Jodhpur in the 1930s by the maharaja, who went up in his aeroplane and scattered seeds out the window. No one knows why for sure, but there is some suggestion the maharaja thought the plant could be used to produce aircraft wheels, many of which would be needed as a world war approached.

The plant's combative nature was compounded by animals that entered the fort through gaps in its crumbling walls and grazed on only native species.

Cutting back baavlia to ground level causes it to sprout with redoubled vigour, and using chemicals was never an option in an area where water runoff is collected and used. Krishen says he was given "busloads of cock-eyed advice".

Eventually, help came in the form of highly skilled rock-miners whose ancestors had, 500 years earlier, chiselled the gigantic blocks of sandstone used to make Mehrangarh Fort.

The secret to eradicating baavlia entailed digging down at least 15 inches below the soil level, where its budding zone lies in its upper root system. But that revealed another obstacle: the volcanic rock rhyolite, which is harder than granite. Fortunately for Krishen, the rock-miners found a way through. He hired 13 of them for his baavlia-removal squad. After three months, they had excavated the invader from less than one hectare of rocky land. Krishen used this as an experimental plot.

After the first monsoon, he planted 2,000 plants in pits from which the baavlia had been eradicated. Within a couple of months, 70 per cent of the desert ephemerals and grasses they had planted were surviving.

As work continued, Krishen took short forays into the desert looking for other species. He enlisted the help of Professor M.M. Bhandari (known as Doct-saab), the doyen of botany of the Thar Desert. Nearly 80 years old, Doct-saab would sometimes direct desert explorations from his home, drawing on memories of trips he had taken in the area 30 years previously.

"I would get instructions like this," says Krishen: "'When you find the temple near Barmer, start climbing the small hill behind it. Within 200 to 300 yards you will find small crucifers. Look carefully. White flowers. Four petals with a touch of orange in the stem. That's Farsetia. This is the only place you will find Farsetia in India.' Sure enough, I found Farsetia micrantha, less than knee-high, a touch of orange in its stem, somehow clinging onto life 30 years later in the pedi-ment of a hill. The only place in India. Wow!"

Planting continued over the next couple of years, only to take a setback in 2007, when the rains started early, stuttered and petered out entirely. This arid region is dependent on the annual monsoon, which comes between late June and early September and offers a growing period of four to six weeks. "Four or five twiggy inches of growth a year is about the best you can expect," says Krishen.

His nursery of seedlings was doing well, however, with more than 8,000 plants of 60 species being lovingly tended. At the end of 2008, Krishen acted on what he calls "sand envy" and created a small plot of salty sand for salt-loving plants. This added another 11 species to the garden's list.

Over the next couple of years, Krishen developed the first visitors' walking trail, following an old aqueduct that passes under the fort wall. Studded with the region's lithophytes (plants specially adapted to rocky habitats), the trail opens out to offer splendid views of the fort, making for a dramatic 15-minute walk. Work on the visitors' centre inside the imposing gateway also got underway. The entrance to the park is tiled in naturally rippled slabs of red sandstone in a nod to the traditional architecture of Jodhpur.

There are now 140 species of plant growing inside the park, and Krishen plans to increase that to 250. Nightjar and Scops owls are frequent visitors, as are other nesting birds and a plethora of insects.

Late July to October is the best time to visit the park, when the rains turn the land a lush green. Herbaceous plants tend to flower two to three months after rain while many of the tree species flower from February to April.

Mehrangarh Fort was built by Rao Jodha (1416-1489), who moved the capital of the Rathore clan of Rajputs of northern India to Jodhpur in 1459. Located on the eastern edge of the Thar Desert, it is one of biggest and most magnificent forts of India. It rises 122 metres above the "Blue City", so called because the buildings of Jodhpur are painted indigo.

Just like the fort, the garden is a symbol of man's mastery over his environment, but it is also a celebration of the power of nature, a force that feels both unforgiving and obscenely generous in this harsh, dry land.


Getting there: Jet Airways ( flies from Hong Kong to Delhi, and from there on to Jodhpur.