Plant some catnip in an area away from your other herbs and the cats will hang out there. Also, I've noticed that my cats don't like scented geraniums(especially the citrus scented ones)...maybe you can plant a couple of those among your other herbs.

Roses. Thorns are unfriendly to soft paws.

FataMorgana

anti-pigeon spikes (little plastic sharp thingies on a plastic base) between the plants works well. The catnip in another area works well, too! In a pinch, try plastic picnic forks pushed handle down in the ground so the tines stick up. I have used wooden pointy grilling sticks but sometimes you forget they are there and spear yourself - ask me how I know.

batya, that is exactly what i was thinking of doing. i was thinking nailing couple nails into hardboard and set it there, but i was worried i will forget and step on it. forks or pigeon strips seem like good idea. where are pigeon strips available? i guess i will try home depot first. i dont want to plant any roses or turnip.
things i have tried so far that didnt work: vinegar, orange peels, planting lemon thyme, throwing rocks...
steel need to try to sprinkle cayene pepper and mustard mixture .

Twiggy prunings spread around the plants - especially rose prunings. It will annoy the cats but not hurt them. Unlike the nail idea which I think is dangerous to both gardener and cats. There's also a small patent water squirting scare crow device which is meant to deter cats.

slow process but I have been trapping cats that hang around my yard & call animal control to pick up. Have gotten rid of 11 in 3 months & that is with a long spell off after a death in the family. I haven't even seen one in my yard since last 1 trapped 2 weeks ago.

No, no, please don't use cayenne pepper or hot mustard for the cats. They step in it, rub their eyes when they clean their face, and nearly scratch their eyes out with the burning and pain. It's needlessly cruel, no matter how much you want them out of your herb patch or anywhere else. Like you can see, there are many other ways..........