Very nice find man, don't go telling anyone about it - even people you think you can trust. You will wake up one day and see the DEA back there doing a little landscaping/fall cleanup, lol.

You should let it grow, you will get a nice harvest once it's ready. 100% natural is always best, especially if it is flourishing with no additional help from people.

Be careful, though you found that and that fact that you have seen people with loads of it, probably means there's a bigger field of that shit somewhere close by that does belong to someone. Probably some really big time drug dealer in your area. As a result, some seeds were prolly dropped as him and his buddies were cleaning out one or a few times, and got you a lil crop on the side..

Just be aware of whats going on and don't get yourself in to shit. Again, very nice find.