That's not what I said. I didn't say they couldn't be grown there; I merely said that they were the owners responsibility. If the plants left the property and became a nuisance for somebody else, the "victim" would then have civil recourse.
It is a slippery slope. As I said, I would prefer it as a totally civil matter. Unfortunately, the biggest weed transporter around here is the County itself, so I don't see a purely civil system having a prayer only because judges are so corrupt in their protection of government interests. The state already has the right to define a noxious weed and has such a list. What's happened is that they don't list weeds because the power interests don't want the accountability and the system fails.
If I had my way I would call a weed, any non-native vegetation. If the plant moves so fast that it justifies a lawsuit, so be it. If it stays put, nobody would bother. You would have the absolute right to grow all you want; just don't let it leave or your neighbors might lodge a claim against you. If the neighbors don't care then there's no harm done although they inherit a potential liabiiity downstream. That's why there's no civic enforcement at all in the ordinance I proposed. It merely defines responsibility.