Away from jarring city traffic and dusty New Delhi streets, the Upadhyes’ rooftop garden is a lush green haven of vegetables and herbs, even after the summer rains have drawn to a close.

The couple, both freelance filmmakers, said they visited the local market only twice a month this season. Before, they went every two days. Their produce — including okra, coriander and amaranth — came from four 16-square-foot planting boxes filled with a careful mix of soil and seed.

“Eating what you grow is a different kind of joy,” said Yamini Upadhye. “In the middle of dinner I run up to get some fresh basil and add it to a dish. The quality of a meal changes.”

With their terrace experiment in full bloom, Nitin and Yamini Upadhye have joined a small but growing number of families trying to adopt sustainable, eco-friendly practices in India’s smoggy capital, and for good reason. In terms of air quality, Delhi is the most polluted city in the world, according to a World Health Organization report. And a study by the city’s health department revealed that 70 percent of all running water is impure.

Prime Minister Narendra Modi is making an effort to appear green, cracking down on cosmetics tested on animals and launching a quest to make India a leader in addressing climate change. And the WHO report motivated the New Delhi transport department to build a cleaner public transportation system.

Still, Delhi families seeking to deploy renewable energy or grow food work with little of the guidance or government support available to residents of Europe or even the US. Meanwhile, they contend with power cuts and choking smog.

“There is a lot of potential going forward,” said Anurabha Ghosh, the CEO of the Council on Energy, Environment and Water, a nonprofit policy and research group. “But there are also great challenges.”

Kamala Ratnam, a South Delhi resident, said her late husband didn’t shy away from those challenges when he installed a 3.5 watt solar energy system on the rooftop of their apartment building in 2010.

After five years of studying solar energy, Chudamani Ratnam, who led an Indian oil company, had fashioned a relatively large system of sixteen solar panels that gives the household at least six hours of energy per day and supports an electric stove and air conditioning unit.

While neighbors and friends have been inspired, Ratnam said the system sometimes comes at a high cost — about 16,000 rupees ($300) to replace each of the batteries. Many people, she noticed, also feel overwhelmed by the technology, especially without a clear-cut place to go for guidance or financial assistance or subsidies.

“My husband was a man of science, it was a passion project,” she said. “Not everyone can do it.”

That gap in access to information and technology is part of the reason for India’s untapped potential when it comes to renewable energy, Ghosh said. According to one study released this year, there are only 700,000 solar water heaters in Indian households, though almost 45 million have the capacity to use these cost-effective, readily available systems.

Another limitation is government policy. In 2010, India launched the Jawarharlal Nehru Solar Mission, a government program to deploy 20,000 megawatts of grid-connected solar power in the country. But much of this push for renewable energy has only been focused on rural areas, and it hasn’t always been successful.

Luckily, Ghosh said, the surge in eco-entrepreneurs has also risen to meet the demands of a more aware and conscious public. “Historically there was no business model around this.”

That’s what Amit Dhingiya and Mridu Mahajan, founders of Nirvaaha Organics, discovered when they launched their organic grocery store in 2011.

Nirvaaha, a quiet store in Delhi’s Defense Colony neighborhood, is fragrant with dried spices and grains. “People are tired of hearing about pesticides and poison in their food,” Dhingiya said of Delhi’s growing awareness of organic food.

Many studies support the dangerous impact of pesticides on cancer rates in India, and elsewhere. In recent decades, respiratory illness and even lung cancer have become rampant in Delhi.

Nirvaaha is careful about sourcing their products from producers that care for both the land and their harvests. They work with local farmers for their chemical-free produce, and get fresh milk from a nearby dairy that doesn’t pump any hormones into their cows. These careful choices, Dhingiya says, are why his customers trust him.

But for him it’s more than a business model. The 34-year-old entrepreneur and Mahajan also host community cafes, cooking classes and workshops on gardening to help more families like the Upadhyes have a choice in what they consume.

“It’s a shift in consciousness,” Dhingiya said. “It’s slow, but it’s growing.”

Watering the plants in his garden, Nitin Upadhye checked the newly growing spinach leaves and pulled out some dried-up carrots from the bed on his roof. As he and Yamini discussed what they would be growing as the winter season arrived, he mulled a more personal reason for tending their first garden.

“In Buddhism we have the concept of oneness with the self, the environment,” he said, chewing a fresh spinach leaf with a salty taste. “To me this is an attempt to live in harmony.”