Feminized, or fem , varieties offer a simple solution to these issues, as there is no need to spend time during their first days in flower checking for males, nor energy removing and destroying them once they are identified. Guide Growing in soil. Weed seed banks are the primary source of persistent weed infestations in agricultural fields Cousens and Mortimer, 1995 and if their deposits are increased, greater herbicide doses are required to control weeds afterwards Taylor and Hartzler R, 2000.  Source: [url=https://masani-art.de/cannabis-seeds-101-a-comprehensive-buyers-manual-2/]https://masani-art.de/cannabis-seeds-101-a-comprehensive-buyers-manual-2/[/url]