'Tis said..."If you set it, they will get it. If you sow it, they won't know it."
The idea being that if you're handling it, you're releasing the oils and consequently the scent and they will smell it (cats)
I grew nepeta but finally gave up because once our cat happened upon it, he would return and return and return....smash it down, roll in it, drool all over it...lol..
Where we are now we do have a lot of neighborhood cats who spend a lot of time in our yard so I won't even try to grow it...though I do love it.