This raised a question in my mind about the extent and nature of property rights. I've never bought the Lockean story about property rights -- as Susan Okin has argued (against Nozick), it seems that if you take this far enough, then our mothers (and possibly our fathers), since they make us, thereby own us, and can transfer us to whomever they choose like any other piece of property.1But this then leaves property rights quite hard to understand.
My general sense at this point is that my private property rights only exist in a very weak way -- that is, whenever there is no stronger right or duty to override them. And the (mild) public health concerns and (much stronger) environmental concerns which seem attendant on chronic, long-term use of weedkiller and lawnfeed seem like just such overriding forces. Hence, the incoherence of the argument on this little notice: no one has an indefeasible private property right to dump chemicals on their lawn (and, consequently, into the groundwater and into the rain, and thus the water supply generally). Unless, of course, our mothers can buy and sell us like any other piece of property.