what do you mean? if you mean you smoke a joint then blow it on the plant then not really except for the little bit of carbon dioxide you're giving to the plant via the smoke, but other than that; nope.
its most likely damaging on a moleculer level to your cannabis plants, i would suggest against it. too many chemicals are being burnt therfore turning into diffrent chemicals. im sure at least 1 of them is somehow toxic to plant life in general. tobaco for instance will kill your crop.
The process of smoking causes a by product of carbonmonoxide. It goes to your blood stream and stays there, till you haven't smoked for a few days. You exhale this also when you smoke, so no, smoking around your plants probably isn't benificial. I don't think it will hurt them, unless you really Cheech up the place though.
