This spring I journeyed to San Francisco to celebrate the 48th anniversary of Earth Day with dharma friends practicing at the San Francisco Zen Center. We began the day sitting in meditation, establishing our internal dedication to peace and nonviolence, the theme of our time together.

The SFZC is no stranger to violence. In 1979 one of our young students was murdered on the streets of San Francisco not far from the downtown temple we call City Center. Four decades later, inner and outer actions dedicated to peace for all beings continue to be at the core of the sangha’s embodied Zen practice.

Our Earth Day celebration was followed by lively dialogue on the art of engaged peacemaking and a chanting and planting ceremony held in City Center’s inner courtyard.

At the center of this urban temple a stately Japanese maple tree grows more than three stories tall, spanning heaven and earth. A Zen friend reminded me that this iconic maple was originally gifted as a tiny bonsai plant to Zen priests Lou and Blanche Hartman, two of the most beloved teachers to have practiced at SFZC. Concerned that their small bonsai required more open air, Blanche transported the muscular little maple out to the courtyard garden, where it soon shattered its miniscule container, taking deep root in the heart of the temple garden.

Related: The Zen of Not Knowing 

Our Earth Day ceremony unfolded in the green and dappled domain of this now-mighty Mahayana maple. We scattered fragrant flower petals at the root of the tree, chanting the Metta Sutra of lovingkindness and offering homage to the stream of ancestral plant, animal, and human teachers who fearlessly and compassionately open a path of practice beyond all concepts.

After chanting, we dug into the dark spring earth and planted lavender for compassion, rosemary for wisdom, and white sage for clarity of heart and mind. A few of us continued to sit in silence under the courtyard maple after the ceremony, as a vibrant Earth Day march for life surged through the streets of San Francisco surrounding us.

During this Earth Day of practice I often called to mind two young leaders who inspire me with their radical nonviolent activism. My association with Kyle Lemle, whom I’ve known since he was a child, deepened a number of years ago when he formally entered Zen practice at Green Gulch Farm. He now works as an ardent community forester and environmental activist. A gifted musician, Kyle serves as founder and co-director of the Thrive East Bay Choir, a socially active vocal group in Oakland, California, where he lives at the dynamic intersection of spirit and service.

Kyle met Brontë Velez in 2016 when each was awarded an inaugural nine-month-long Spiritual Ecology Fellowship. The daughter of a dedicated Atlanta pastor, Brontë is an emergent poet and artist committed to restorative justice in her own black, brown, and indigenous communities.

Working and practicing together, these two young leaders founded Lead to Life: A People’s Alchemy for Regeneration. Animated by a common commitment to nonviolence and the conceptual disarmament tradition known as Swords into Plowshares, Brontë and Kyle had a clear vision of transforming actual weapons of destruction, primarily firearms, into digging shovels to be used for ceremonial tree plantings at sites long impacted by violence.

In a nation where more than three hundred million firearms are in civilian hands and guns have been responsible for one and a half million deaths over the last five decades, the young founders of Lead to Life wasted no time in realizing their vision. Passionate and practical, they had a dream. Fully awake, they manifested that dream.

On April 4, 2018, the fiftieth anniversary of the shooting assassination of Dr. Martin Luther King, Jr., Lead to Life took its first action in Atlanta, Georgia, where a Minnesota-based metal artist transported a cache of legally disabled guns and a portable foundry furnace. For a week, active faith, creative ceremony, and powerful resistance and resolution wound together in a dynamic braid to unite the city. Bernice King, the youngest child of the King family, picked up a handgun for the first time in her life and delivered the weapon to the heat of the refiner’s fire. The gun became molten metal and was transformed into a digging shovel just a few blocks away from the tombs of Dr. King and Coretta Scott King.

That week, Lead to Life melted 50 guns into 50 shovels, and with the will of peaceful nonviolence 50 new trees were planted in Atlanta. To initiate this effort, a young cherry tree was dedicated at the King Center for Nonviolent Change with the blessings of two 16-year-old African American students from Marjory Stoneman Douglas High School in Parkland, Florida, where a mass shooting caused the deaths of 17 people on February 14, 2018.

Related: What is the Mindful Response to a School Shooting?

In the cool shade of the courtyard maple I imagined fiery Brontë planting a young Eastern Redbud tree on the streets of her home city, exactly where her 21-year-old close friend, X’avier Arnold, was shot to death by a 14-year-old boy on the day after Christmas, 2013.

Surrounded by family and friends, and grieving for a teenage murderer now serving three lifetimes in prison, X’avier’s mother mixed a handful of her son’s ashes with raw soil that she had gathered from a lynching site in Roswell, Georgia. The beloved community gathered close around her. There in the heart of Atlanta, they opened the ground and planted X’avier’s memorial tree, using a new shovel forged from weapons of destruction.

With inner disarmament we also need external disarmament, the Dalai Lama taught at the University of Virginia in November 1998. The person who is your enemy today, he added, “if you treat them well, the next day will be a good friend.” This radical insight fills my heart and mind. Buddhist practice and the work of nonviolence can never be separated. They are fused together with spiritual insight and dedicated action and enlivened by a continuous alchemy for regeneration.