The Kill Bill actress, 45, and about 25 immigrant farmers and their supporters were campaigning to save the 14-acre fruit and vegetable garden from planned demolition.
"I spent the last 23 days down at the South Central farm, which is the largest urban farm in the nation and provides food for hundreds of families," Hannah tells PEOPLE. "The subsistence farmers are from one of the poorest communities. This farm should be a model for sustainable urban agriculture. It needs to be replicated, not eradicated."
For the past three weeks, Hannah and protest organizer John Quigley had been sitting 40 feet above the ground in a large walnut tree. Folk singer Joan Baez and anti-logging activist Julia "Butterfly" Hill had also taken shifts in the tree, although neither was present when the arrests were made.
Ric Francis / AP
Los Angeles Sheriff's Department spokesperson Kerri Webb said the protestors were arrested for violating a court order and obstructing sheriff's deputies who were enforcing the order, two misdemeanors.
Police arrived at the garden without notice at 5 a.m. Tuesday, but because some demonstrators had attached themselves with "chain links, handcuffs, and 55 gallon steel drums filled will cement," it took officers several hours using power tools to break through the devices.
"Arrests were made from 6 a.m. in the morning until 1 p.m.," said Webb, adding that no protestors or deputies were injured.
Leonardo DiCaprio and Willie Nelson had also stopped by the garden in the past weeks to show their support.