Use: You are allowed to use cannabis in ACT, but not in public places or near children.Possession: If you are over 18, you are allowed to possess up to 50g of dry weed or 150g of fresh cannabis nugs.Growing Cannabis: If you are over 18, you are allowed to grow up to 2 marijuana plants and a maximum of 4 plants per household.In General: Marijuana is Legal in Australian Capital Territory as long as you are over 18 and you follow ACT cannabis rules.Here is a quick recap of the most critical aspects of the legality of cannabis seeds in Australia: In Australian Capital Territory (ACT): We know - the legality of possession and use of marijuana and/or growing marijuana seeds in Australia is complicated.