Sudbury's Acid-Scarred Hills Limed and Replanted: 3,500 Hectares, 10 Million Trees

Around Sudbury, a century of smelter emissions and logging left barren, acidified hills. The City of Greater Sudbury's Regreening Program has limed and grassed more than 3,500 hectares since 1978 and planted more than 10 million trees. Its 2025 annual report records 105,619 seedlings planted that year (10,429,179 since 1978), 5.5 hectares newly limed (3,517 hectares in total) and 20 schools with 1,125 students taking its classroom programme between September and December 2025. In 2024 the program created 28 temporary jobs. Mining company Vale Base Metals also aerial-seeds additional barren land in partnership with the City.