guerrilla gardening
noun [ U ] uk/ɡəˌrɪl.ə ˈɡɑː.dən.ɪŋ/ us/ɡəˌrɪl.ə ˈɡɑːr.dən.ɪŋ/
（未经允许在其他人或公共拥有的土地上进行种植，目的是为了改善环境或生产蔬菜花卉供人使用或欣赏的）游击队式园艺
the activity of growing plants without permission on land that belongs to someone else or on public land, with the aim of improving the environment or producing vegetables or flowers for people to use or enjoy