I've always grown catnip, for the FatCat and friend's cats. They say my homegrown stuff makes their cats go much much crazier than the lame store-bought dirt-weed.
I eventually graduated to a, like, 20 or 30 gallon ceramic pot. I haven't had to reseed or replant for years, because the roots (?) live through the winter and it just comes back on its own. It's technically a mint. You can't kill it.
I was making The Big Harvest, which I dry each year , so kitty can get stoned in the winter too.
My wife came to take a look at the harvest.... when she noticed....
the hundred catnip plants growing in her garden and flowerbeds! She knows it grows and spreads like a weed and can't be killed and now it's loose on our property, to attract all the feral and barn cats for miles around.
It can't be killed.
It's not like I did it on purpose.