eheathDon't call the cops, its just weed, trespassing is more serious to me then someone growing weed, but this could work out in your favor.
Ehhh its really not just weed, its a giant pile of growing money. Even if weed and its typical smokers are chill, ANYONE dealing with big money illegally is going to want to keep all of that money. Even if they're down to make a deal, theres a real chance they won't be. And then what is your plan?
For every chill stoner there is another totally unchill greedy dealer trying to hustle someone. The higher up the weed chain you go, the more greedy they get. The honest ones grow on their own land. I would most deffinitley not try to make a deal outright, OP doesn't even know for sure they werent there hiding when you discovered it.
If it wasn't your own property, or it was just a plant or two, I would tell you to take a bit, or try to talk to them to get a few nugs. But you stumbled on big money. People take big actions to protect big money. Don't be on the wrong end of it.