If California Legalizes Marijuana... ...you'll be able to carry an ounce, grow 25 square feet of it By Jane Yager, Newser Staff Posted Mar 25, 2010 8:35 AM CDT 53 comments Comments In this photo taken May 13, 2009 marijuana for medical purposes is shown inside a greenhouse at a farm in Potter Valley, Calif. (AP Photo/Eric Risberg) (Newser) – California's ballot initiative to be considered this November would legalize use and sale of marijuana—but exactly how much pot are we talking? If the initiative passes, adults over 21 will be allowed to possess up to an ounce for personal use, and each residence would be able to grow up to 25 square feet of it. Cities and counties will also have the option of allowing and taxing marijuana cultivation, transportation, and sale. Currently a slim majority of California voters is in favor of the measure. Advocates hope to convince undecided voters—a group that consists largely of mothers—with arguments that legalization would undercut drug cartels, free up police to fight more serious crime, and make it harder for teenagers to buy marijuana, the Los Angeles Times reports. Opponents say legalization would increase marijuana use, thus adding to social problems and putting more demands on law enforcement.