Hidden garden holds the secrets to sustainable greenery in the desert

Thriving vegetation, such as this large neem tree and bougainvillea, have survived in an abandonded housing complex at Jebel Ali without irrigation. Delores Johnson / The National

An abandoned villa complex in Jebel Ali is an unlikely location for clues to the UAE's long-term sustainability, but the lessons learnt there will help make the Emirates a greener place.

It's the cactus that really brings the message home. Or, more specifically, the dead and shrivelled remains of a cactus that once graced a family garden but withered under the relentless Arabian sun as soon as the water was cut off.

If a cactus - that acme of arid-climate adaptability - can't survive without irrigation, what chance does any plant in the UAE have?

But just a few steps away and still within the apocalyptic-looking enclave of abandoned villas at Jebel Ali Village is a tree that is not just surviving but thriving years after its irrigation was stopped.

The neem tree is the most discordant of the dozen or so species that have survived. It features strikingly green leaves and is doing so well that it is now taller than the villa that once sheltered it. In fact, throughout the complex, plants are doing just fine without irrigation, even if they are outnumbered by species that lie as dead and desiccated husks.

This enclave of dilapidated, forgotten villas wasn't intended to be an experiment in horticultural Darwinism. At one time, the homes, ageing yet still comfortable, with established gardens and located near Ibn Battuta Mall, had been scheduled for redevelopment. But after the tenants left, the global financial crash scuppered those plans and, ever since then, the enclave has sat fenced off from the rest of the world.

The neem tree is valued for its many medicinal uses in the subcontinent, but some in the UAE - ranging from horticulturalists to the Abu Dhabi Urban Planning Council (UPC) - are saying it and similarly drought-tolerant species are equally valuable here by demonstrating that the much-prized verdant foliage is not dependent on irrigation.

The emirate is midway through the process of a fundamental change in direction, both in the types of gardens being created and in the way they are watered. Previously, extensive green spaces were created featuring lawns and flowering annuals that would be familiar to residents of countries with far wetter climates.

To create those in the UAE requires extensive irrigation using a combination of desalinated water and, more recently, treated wastewater, completely at odds with the country's sustainability goals and recent warnings of future water shortages. And the UPC recognises this; in new planting rules issued last year by the organisation for all of Abu Dhabi's future public areas, lawns are out of fashion and drought-tolerant species are in.

But while the UPC was preparing its rule book, the plants at Jebel Ali were showing the way.

On a baking hot, mid-May morning when just standing still is enough to leave you bathed in sweat, it's hard to believe anything could survive in this environment without help. The ubiquitous black irrigation piping around the villas shows gardens here used to rely on water just like similar complexes all across the Emirates.

For Nick Leech, an Abu Dhabi-based landscape architect and contributor to The National, the abandoned villas of Jebel Ali are the foil to the "incredibly wasteful" approach of the UAE, and particularly Abu Dhabi, to its aim to green the desert.

Leech says the quick demise of most of those plants, even including native but water-dependent species, demonstrates the unsustainability of how things have been done.

"The exotic plants which tend to dominate planting schemes here in the UAE soon died, whereas plants that were actually more suited to local conditions of extreme heat and lack of water are either hanging on or, like the bougainvillea, are actually thriving," he said.

"This is an object lesson for what future planting schemes in the UAE might look like and which plants are better suited to use in situations where water is becoming more of a priority."

Around a dozen species have survived years of neglect at Jebel Ali Village. Some, such as the Indian banyan tree, have seeded and propagated a new generation. Many of them feature in the UPC's rule book, the Abu Dhabi Public Realm Design Manual, which requires that at least 80 per cent of the landscaping in public areas consist of locally occurring, drought-tolerant plant species.

The neem tree is described in the manual as an "excellent urban tree for streets, public plazas and parks. Very successful in Al Ain". The Indian banyan tree is also recommended as a "good street and park tree providing dense shade in a climate where shade is critical".

The date palm is rated among the thirstiest of the species approved by the UPC. But the design manual notes that date palms are "essential in both a cultural context and as urban shade". Their water use - up to 80 litres a day - is concentrated during growth periods, making the overall annual consumption about the same as any tree of similar stature.

They are among more than 100 recommended species cited in the UPC manual that have been assessed as appropriate for Abu Dhabi's climate and rated according to their water needs, hardiness and potential hazards such as thorns or poisonous sap.

All public spaces in the emirate will have to include species for planting from the approved list. Turf is only permitted in limited circumstances for some public parks, with synthetic turf preferred in active-use areas such as sports fields. In stark contrast to the uses until now, turf is banned entirely from use in conservation or desert parks.

But selection of species is just part of the approach. Far more efficient irrigation, including using treated wastewater rather than desalinated water, will help steer Abu Dhabi away from the notoriety of being one of the world's heaviest water users per capita.

The Dubai Desert Conservation Reserve is demonstrating how it can be done. Instead of using surface irrigation, in which much of the water is lost through evaporation, drip-irrigation systems buried 40cm deep around the reserve's date palms have cut the daily water usage by more than half.

The reserve manager, Greg Simkins, also points out groves of ghaf trees, a species that exemplifies the desert landscapes in the Emirates.

"What we've done here with these trees is different. We've stopped the water for the last two years and as you can see the trees are still in perfect shape.

"I think this is the way forward for the authorities to look at reducing water and eventually stopping water to these trees because they're adapted to this environment."

If anything, private gardens are lagging behind. Go to garden shops such as the Desert Garden Centre in Abu Dhabi's Khalifa Park or its sister company, Dubai Garden Centre, and the stock suggests people are far more interested in recreating Bali than Bahrain. Still, the company also deliberately provides alternatives such as the desert rose, a native of Oman and Yemen that is far better adapted to the UAE climate.

UPC associate planner Kevin Read said his organisation's list of approved plants is a deliberate collaboration between the UAE's nurseries and includes plants that are not available commercially.

"First of all, the UPC researched the current commercial market availability of plants in the UAE and in particular the local suppliers in Abu Dhabi. By simply categorising the limited number of indigenous plants found on the nursery stock lists, we were left with a long list of other plants which are typically imported from all over the world," he said.

"The UPC worked with local horticulturists and consultants to identify which of the plants on the market have the lowest irrigation demands and greatest drought tolerance based on their observations in practice.

"We then shortlisted those plants that offered the best solutions in terms of their irrigation demands, behaviour, physical characteristics and, of course, ideal function in the public realm."

The end result is that native plants that have been overlooked until now will become more popular and be grown commercially, he said.

"We have found that as a result of engagement and consultation with local nurseries and suppliers that they, too, over recent years have started to propagate and experiment with the potential of using native plants in the local domestic market. We eagerly await new native plants to join our plant list."