I'm not a lawyer and this is not legal advise, but according to this Property Disclosure form, it seems reasonable to assume the previous owner had knowledge of non-compliance and could be accountable if not disclosed.
http://www.unlimitedmls.com/forms/Pr...osure-Form.pdf
Also seems compliance assessment could be a business opportunity for someone like a home inspector to include landscape non compliance in their assessment.
Buyers need also to be accountable to perform their own due diligence. In tue end, it will be their problem.