In Detroit’s eastside, arborists have embarked on an initiative to transform vacant lots into an urban forest featuring the world’s largest trees, the giant sequoias. Although not native to the city—where elms, oaks, and red maples usually grow—these majestic trees are being introduced with the goal of replacing urban blight, enhancing air quality, and aiding in the conservation of species endangered by increasing wildfire severity in California’s Sierra Nevada.
The Giant Sequoia Filter Forest has selected Detroit as its pilot city. The nonprofit Archangel Ancient Tree Archive provided countless sequoia saplings, which were planted on Earth Day by Arboretum Detroit staff and volunteers. These saplings currently stand at about a foot tall, but are anticipated to reach approximately 15 feet within a decade. Arboretum Detroit has already seen success with earlier plantings, where 11 sequoias now stand between 12 to 15 feet tall on other vacant lots, and another 200 saplings are ready in their nursery. Archangel plans to extend this initiative to Los Angeles, Oakland, and London.
Giant sequoias, known for their impressive growth — they can stretch over 300 feet in height with a trunk diameter of more than 30 feet — have lifespans exceeding 3,000 years. Andrew “Birch” Kemp from Arboretum Detroit emphasizes that these trees, when matured, would create a protective canopy in the neighborhood. Despite their resilience to disease and fire, climate change poses new threats from increasingly intense wildfires out west.
The sequoias planted in Detroit descend from storied giants: Stagg and Waterfall, two ancient trees from the Alder Creek grove in California. Archangel began the process of cloning these sequoias in 2010 by collecting cones and clippings. Unfortunately, a wildfire in 2020 devastated the grove and destroyed Waterfall, although Stagg remains. Both trees will now have a legacy in Detroit.
With a significant population decline from its 1950s peak, Detroit offers the space needed for these sequoias to thrive. Today, only a fraction of the original homes remain in some neighborhoods, leaving room for reforestation efforts. Kemp views this as an opportunity, hoping that the city might become the greenest urban area in the world, benefiting from the absence of the wildfires that threaten these trees elsewhere.
The preservation and care of these sequoias are intended to be a community effort, with Archangel’s co-founder David Milarch advocating for “tree school” programs to educate the youth about environmental stewardship and tree care. Since Detroit’s residents face significant air pollution challenges, the sequoias are expected to have a substantial positive impact, particularly in industrial areas with high asthma rates. Kemp’s nonprofit has already planted some 650 trees on about 40 lots to combat air pollution and other urban environmental issues.
These efforts, particularly with the sequoias, aim to drastically improve air filtration, create shade, and enhance the overall urban environment. With their rapid growth and evergreen nature, sequoias might be the ideal candidate for tackling the city’s pollution and stormwater management problems.