A retiree planted 40,000 trees on a São Paulo wasteland — it's now the city's biggest park

In 2003, retired food-industry executive Helio da Silva began planting native saplings on a degraded 3.2-km strip along the Tiquatira stream in eastern São Paulo — land that had become a trash-strewn haunt for drug users. Working alone, funding it from his own savings (roughly $7,000 a year), he researched the area’s origins in the Atlantic Forest and chose over 170 native species, planting one fruit-bearing tree for every twelve to draw wildlife. Early efforts were repeatedly bulldozed by local businesses, but he simply replanted at larger scale each time.

By 2007, with 5,000 trees standing at an 88% survival rate, the city formally recognized the site as Tiquatira Linear Park — São Paulo’s first — which brought municipal protection, infrastructure, and expert help. The park now holds more than 40,000 trees across roughly 160 species, hosts 45-plus bird species, runs measurably cooler than surrounding pavement, and absorbs an estimated 40% of the heavy rainfall that once flooded nearby streets. Da Silva, now 73, aims for 50,000 trees.

Beyond the individual achievement, the piece frames the park as a case study in urban forestry’s documented co-benefits: carbon capture, air-pollution filtering, stormwater management, biodiversity corridors, and measurable mental-health gains for nearby residents — a low-tech, grassroots model for climate resilience in dense cities.