This is achieved through a process called feminizing , which involves manipulating the genetics of a female plant to ensure that it produces female seeds. undefined undefined Getty Images Giant ragweed is a summer weed named for its ability to grow up to 15 feet tall, with thick roots and branches. 2023 CBS Broadcasting Inc. Source: [url=http://ubdays2017.universityofbohol.edu.ph/2013/06/21/hashish-seeds-marijuana-seeds/]http://ubdays2017.universityofbohol.edu.ph/2013/06/21/hashish-seeds-marijuana-seeds/[/url]