I spent about 2 years in northern Kazakhstan and there were places where cannabis grew wild. There was one place I visited on an island in a lake with 6 foot tall plants growing thick over more than an acre.
That has me thinking today about how they grew? Presumably, the seeds fall and germinate in the soil, generating new plants every year? Plants also grew wild in the suburbs of Almaty, but the local authorities cut them down before they would flower. The next summer, they would be back. How does this happen?