A friend has some growing her in back yard. She says it can literally take over the entire garden if you don’t keep it trimmed - grows like a weed!
It thrived here in Pennsylvania for several years, but our crop nearly got wiped out totally last year because it was hot and dry. Catnip likes just a little shade and cool, relatively wet weather.
Some of the most potent catnip, however, is grown in dry climates like the Rocky Mountain valleys with just a minimum of watering.