Not recommended, really damage is done, punishment will not undo the damage. What I would do is educate my son the danger of Marijuana which I already did. He knows I smoke from time to time and I told him that I regretted trying it but I love it. I will be extremely disappoint in him if he does before 21 years old. After that I don't give a damn. I even warned him if he gets that first taste, they won't be his last joint, or even brownies, and other edible ones
The best parents could do is share with young about the danger of drugs. Be open, show respect and show that you care about their future. You could explain your experience with them. They (Kids) wii be likely to honor parents request that is realistic, for example, please wait until 21, because your mind won't be mature until 21, so after that the less damage it will be (It is fact). Show your kids that you don't own them, and let them know that you can't watch them 24/7. kids will likely to think, oh my parents know what they are talking about, and I don't like the idea of betray trust with them. Bottom line, it is all about respect.
For me, all my childhood, I did actually thought I will never turn into adult, because I was in military style in school. Just follow the order or else. Later I realize that I grew up and had some regrets. This includes first experience with Cannabis, I wish I know this shut, and I would have avoided and may never smoke weeds and likely to have deep fear in them.
Because of that, I knew it is harmless at most, it gave me control on my ADHD. I was able to slow myself down, less prone to panic toward any incident that I may not like, for example getting parking ticket in the mail!
Now you see the value of education when it comes to danger of these mind altering chemical.
