I grew weed on accident kinda like the same way you did, throwing seeds to roll a blunt. Had one sprout right behind my garage and didnt notice it til it had about 6 sets of leaves on it. It looked really beat up I dug it up put it into a pot outside and about a week later, gone. Fkin kids in the neighborhood cutting through yard n stuff I spose, cus when I was younger I cut through yards and found 2 tall MJ plants and yup, stole them, hung them up to dry, dont even think they were budding, dried it out and attempted to smoke it, how stupid was I, lol.