Can anyone explain this for me?

So. Today and yesterday this guy and girl have been saying how smoking is not a sin and everyone back in the day smoked pot and stuff and Jesus did to. I was trying to prove them wrong but couldn't but I think I had a good point. They kept saying Gen. 1:29 tells them that it is okay.

"Then God said, "I give you every seed-bearing plant on the face of the whole earth and every tree that has fruit with seed in it. They will be yours for food." - Gen. 1:29


I said it dosn't mean making the plant into some joint and smoking it, they meant eating it as is.
Is that right or wrong? And how can I show them Jesus didn't smoke pot and stuff?