This week, we want to tell you what actually happened when we tried to do that.

The honest version of building the Chhaon forest is not as clean as the principle that guides it. We began with a list of native Rajasthani species - drought-adapted, ecologically integrated, the plants this landscape has been selecting for over thousands of years. Neem. Arjun. Khejri. Dhok. The trees whose names appear in folk songs and traditional medicine and the oldest land records of the region. We wanted the forest nodes to be composed entirely of these - a dense Miyawaki planting that was also an act of botanical repatriation.

Then we went to the nurseries.

What the market told us

The nursery reality of Ajmer in 2025 is a reflection of the our priorities that created the vilayati babool problem. What is widely available, reliably stocked, and easy to source is almost uniformly shaped by fast-growth preferences and ornamental demand. Native species, especially the ones with deep root systems and drought adaptations and complex ecological relationships, are slower to propagate and less commercially interesting to most nurseries because their market is small, and thus harder to find.

We stepped out with our ideal list, but what finally came back in the truck was a negotiation between what we wanted and what existed. Some substitutions were forced by availability. Some were chosen deliberately, because Chhaon is also a public space, and a public space that nobody visits cannot demonstrate anything to anyone.

This second reason deserves to be said plainly. We are building a climate experiment, but we are building it inside a knowledge club and co-working space that needs to draw people in. A forest that is ecologically correct but visually austere - all thorny scrub and dry-season leaf drop - will not do the work we need it to do. People have to want to sit inside it. The aesthetics are not vanity. They are strategy.

What went into the ground

The backbone of the planting is where we held firm. Two large Neem (Azadirachta indica) and two Arjun (Terminalia arjuna) form the canopy anchors of the forest. These are among the most ecologically significant trees in the region. Neem’s alleopathic properties (the same chemical mechanism the vilayati babool uses destructively) work constructively here, suppressing soil pathogens and improving the growing environment for surrounding plants. Arjun is a riparian species deeply native to this part of Rajasthan, with dense shade and significant cooling through evapotranspiration. Both have been sourced as mature specimens precisely because we needed immediate canopy contribution to the sensor readings from day one.

We also planted a lot of Mogra (Jasmine, Jasminum sambac), and Mehendi (Henna, Lawsonia inermis). Both are native to or long-naturalised in this landscape, both have deep roots in Rajasthan’s cultural and traditional use, and both add the scent and texture that makes the space feel alive rather than merely planted. The Mogra in particular does something no infographic can: it fills the air with a fragrance inseparable from the memory of Indian summer evenings, producing an immediate emotional connection between visitor and forest that we could not have engineered otherwise. Inarmi and the flowering ground cover varieties fill the mid and lower storey, providing the dense low cover that the Miyawaki method requires to accelerate canopy closure.

The Bottle Brush (Callistemon) was chosen as a strong pollinator attractor - the vivid red flower spikes draw insects aggressively and make the forest visible and alive from a distance. Kaner (Oleander, Nerium oleander), which naturalised along Rajasthan’s water channels and roadsides, provides structural boundary cover and handles the heat without complaint.

Then there are the compromises we want to be honest about.

Bougainvillea, which we have used in abundance is from Brazil, and this obviously not native. It was chosen because it grows easily, provides dense visual cover along the boundary structure, attracts pollinators, and is genuinely beautiful in a way that invites people to step closer. We made the call. Gulmohar is the other one that will raise eyebrows from anyone who read last week’s essay. A single Gulmohar at the edge of a predominantly native planting is a different ecological proposition from the Gulmohar monocultures that line municipal roads. Context and scale matter. But it is still a compromise, and we are naming it as one.

In total, Chhaon will have 21 distinct varieties, over 200 individual plants, across canopy, mid-storey, and ground layers creating the density that distinguishes a Miyawaki forest from a garden.

The gap between principle and practice

We want to sit with this for a moment, because it matters to everything else we are trying to do.

The Chhaon forest is not the forest we originally dreamed of and designed. It is closer to 70% native or long-naturalised species and 30% aesthetic and availability compromises. That is not the 100% we would have chosen in ideal conditions. It is what was possible in the nurseries of Ajmer in 2026, inside a budget, inside a timeline, inside a space that needs to earn its own credibility by attracting the people whose behaviour we are hoping to change.

And this is precisely why the sensor network matters so much. Because the only way to know whether these compromises cost us anything in cooling performance is to measure it. Every plant in the ground is a variable. The data will tell us which ones are doing the work and which ones are occupying space. We will publish all of it - the whole picture, not just the parts that flatter us.

The forest is in the ground. The sensors go in next.

I mentioned this to a local, who smiled in the way people smile when they are about to tell you something uncomfortable. “That green,” he said, “is vilayati babool. The foreign thorn. And it is one of the worst things that ever happened to this landscape.”

What I had mistaken for a thriving native forest was, in fact, a biological takeover by Neltuma juliflora, formerly known as Prosopis juliflora, a thorny shrub native to Mexico and the Caribbean that has become one of India’s most complex and underreported ecological disasters. The story of how it got here is a story about good intentions, colonial ambition, and the particular danger of importing a solution to a problem that already had a local answer.

The intentional invader

The vilayati babool arrived in India in 1857, introduced deliberately to halt what administrators of the time were calling the “desertification” of the Thar. By 1878 it had spread to peninsular India, planted specifically to provide fuelwood to communities facing energy shortages. Decades later, the Maharaja of Jodhpur commissioned what must be one of the more audacious ecological decisions in regional history: the aerial seeding of the species across Rajasthan. Aircraft scattered seeds across the landscape from above. Farmers initially welcomed the shrub as a living fence to protect their crops. It was hardy, fast-growing, and asked almost nothing of the soil.

What nobody adequately modelled was what the plant would do once it escaped those fences. Which it did, and quite comprehensively.

Within decades, the vilayati babool had moved from roadsides into pasturelands, from farmland boundaries into protected nature reserves. Its thorns made it impassable for livestock, cutting off traditional grazing routes. More insidious was its allelopathic effect: the tree releases toxins into the soil that prevent other plants from germinating or growing in its vicinity. The clearing beneath a Prosopis thicket is often a dead zone — nothing else grows. What looked, from the air or from a passing car, like a forest, was in ecological terms closer to a desert wearing a green disguise.

What it displaced

The casualties were not abstract. The Khejri (Prosopis cineraria), Rajasthan’s revered state tree, a species so integral to the landscape that entire communities organised their lives around it, is declining year by year, displaced by its invasive namesake. The Deshi Babool (Acacia nilotica), the Dhok (Anogeissus pendula), the Salar (Boswellia serrata), native species with deep ecological and cultural histories in this region, are suffering similar fates. In Salarmaal, a village historically named for its Salar forests, those trees have almost entirely disappeared, replaced by the invader.

In the Ajmer region specifically, the impact is acute. The village of Ralawatan has seen Prosopis take over 75% of its total land area, including forests and pasturelands. Traditional agriculture in dry reservoir beds, petakasht, has declined by 70%, as the trees block water channels and colonise the fertile silt. The Nandtilora ridge, which once acted as a natural barrier against the shifting sands of the Thar, is losing its effectiveness as Prosopis weakens the native ecosystem that held it in place. The landscape I found enchanting on the road from Jaipur is, in measurable terms, a region in ecological crisis wearing a green coat.

The livelihood paradox

Here is where the story becomes genuinely difficult. Because the vilayati babool, for all its damage, is not universally experienced as a problem. For the landless, for the poor, for communities whose traditional livelihoods have been destroyed by other forces, it has become, however imperfectly, a lifeline.

In Jodhpur district, the Jogi tribe, whose traditional jute business was destroyed by the arrival of plastic, now earns approximately ₹30,000 a month burning vilayati babool to make charcoal. For households where LPG supplies are sporadic or unaffordable, the shrub is the only reliable cooking fuel. Some farmers use the ash from the wood to retain soil moisture for specific crops. The pods, while damaging to cattle, can be eaten by goats and camels, and have been processed into nutritious flour in the Americas.

The uncomfortable truth is that eradicating the vilayati babool entirely would cause immediate harm to some of the most economically vulnerable people in the region. Complete eradication is, as ecologists who have studied this carefully will tell you, neither practical nor just. The species has been woven, however destructively, into the survival strategies of people who had no say in its introduction.

This is the full weight of the imported solution. Not just the ecological damage, but the human dependency that accumulates around it — the way that a bad decision, made once from above, becomes a permanent feature of the landscape of poverty below.

What this means for restoration

The path forward, as with most genuinely complex problems, is not a war but a negotiation, and strategic management rather than eradication. Targeting the invasion front, where the species is actively spreading into new territory, rather than attempting to clear the dense thickets where communities have already built livelihoods around it. Restoring native species like Guggul (Commiphora wightii) and Neem alongside removal efforts, so that cleared land does not simply re-colonise. Turning restoration into employment, drawing on the deep knowledge of local communities who understand this landscape in ways that no outside ecologist fully can.

We think about this every time someone asks why Chhaon wants to use native species first. The vilayati babool story is the answer. It is not a cautionary tale from a distant past - it is happening now, in the landscape visible from the road that leads to our front door. It is the single most instructive example I know of what happens when you import a solution without measuring its consequences, without asking the landscape what it already knows, without giving the people who live there any say in what gets planted above their heads.

Green sovereignty is sometimes treated as a cultural preference, as a romantic attachment to the indigenous over the cosmopolitan. For us, it is a practical position. The organisms best adapted to Rajasthan are the ones that evolved here. The communities best placed to restore this landscape are the ones who have lived in it for generations. Chhaon is being built on both of those propositions - not as as ideology, but as the most rigorous, evidence-based response we know to a problem that bad ideology created.

The green I saw on the road from Jaipur no longer looks like health to me. It looks like a warning. And the only honest response to a warning is to pay attention to it.

People have lived with this heat their whole life. What they’ve have never had - in fact, what nobody in Ajmer has ever had - is a number that proves anything is being done about it.

Heat Action Day observed every year on June 2nd aims to educate communities on the risks of extreme heat and promote life-saving practices to prevent heat-related illnesses. Across the world, organisations and governments share statistics about rising temperatures, heat-related mortality and vulnerable populations. The numbers are real and they are frightening, and the people sharing them mean well. But naming the heat is not the same as fixing it.

India declared its first National Heat Action Plan in 2013. Ahmedabad’s heat action plan (one of the first in Asia) is cited internationally as a model. And yet, in the summer of 2024, India recorded over 40,000 suspected heatstroke cases and hundreds of heat-related deaths in a single season. The infrastructure of awareness is in place. What is not in place, in most Indian cities, is the infrastructure of relief.

We are not dismissing the value of awareness. Heat Action Day exists because heat kills disproportionately, and in ways that are invisible until they are catastrophic. The outdoor labourer, the street vendor, the child walking home from school, the elderly woman in a concrete flat with no cross-ventilation - these are the people who pay for decisions made decades ago about tree cover, about urban planning, about which plants to grow and where.

But there is something we collectively avoid saying: that most of what we call “green infrastructure” in Indian cities is not solving this problem. It is creating the appearance of solving it.

Thirty percent of urban green cover in India’s Tier-2 cities has gradually vanished since 2001. What replaced it was not bare ground - it was asphalt, which absorbs heat during the day and radiates it through the night, keeping cities warm around the clock in a way that no natural surface would. The urban heat island effect in Ajmer adds four to six degrees Celsius above the surrounding rural baseline. On a day that is already forty-six degrees, four extra degrees is not a rounding error. It is the difference between discomfort and danger.

And here is the part that sticks uncomfortably: there is currently no data-verified urban cooling active in Ajmer. Not a single measured, documented, publicly accessible proof point that any intervention is working. Organisations have planted things and held seminars, but there are no measurements. And you cannot fix what you cannot see.

This is what we keep coming back to on days like Heat Action Day:

Chhaon is our attempt to do something about exactly this gap. Not to replace the policy conversation, not to dismiss the importance of Heat Action Day, but to add something that is currently absent: a live experiment, in a real Indian city, with real data, that anyone can access and argue with.

Chhaon opens in Ajmer in July. It is an experiment using Miyawaki forest principles with native Rajasthani species, live sensor nodes measuring temperature, humidity, and soil moisture in real time, and a knowledge hub cooled entirely by the forest around it. The temperature display shows one number: the gap between inside Chhaon and the street outside. That gap - whatever it turns out to be - is the whole point.

On Heat Action Day, we didn’t ask anyone to be more aware. We are already as aware as awareness alone can make us. What we are now asking, and what Chhaon is trying to build, is a place where you can feel the difference with your body, read it on a screen, and take that number home with you.

The heat already has a name. It is past time it had a solution.

Chhaon opens at the Ana Sagar Lakefront, Ajmer, on July 15, 2025. Climate Week runs July 13–17. More at adaptiv.me