zhinu,so true and I hate to say this but the only sure fire method for me was to cage the area with 3 dimensional (ugly) cages where they could not get in. I have used a pet cage to start seedlings when my cat was wrecking them before anything could sprout. If you "shoo" your cat away they will want the spot even more.lol!!!
Another idea is to divide your planting area up so that it has little sections too small for your cat to lie down in. None of my cats can sleep in a gallon pot so maybe if you use a series of different clay pots the cat will not find a comfortable spot.
You can also try carpeted shelves positioned in different higher spots to attract the cats to a resting spot away from your planters.
I wish they had motion detected sprinklers so that when a cat approaches the beds it turns on and the bed gets watered while chasing the cat away. lol!
Karen