I have my salad box in a large mesh jail made of panels to my puppy run including roof, this is the only way I could protect it,if anyone comes up with a good idea please let us know. There is one thing, cats don't like the smell of lemon oil I know that for a fact, perhaps some of those heavily scented lemon pellets from the petshop might be OK in the herb bed, ,I didn't want lemon flavoured lettuces !!
XX Jeannine