Here's a post that might help you - https://cats.lovetoknow.com/My_Cat_is_Soiling_My_House_Plants
Place orange or lemon peels around them. Cats do not like citrus.
Motion sensor sprinklers.
My mother has a spray bottle set on stream. When her cat goes somewhere he's not supposed to, she hits him with a bead of water. It stops him after 1 or 2 times.
Some plants my cats tried to dig in the dirt and I put round river rocks on them so they could not dig. The ones they tried to chew on, I hung with a hook from the ceiling so they could not reach them. Some I sprayed with vinegar, as cats hate the smell and taste of vinegar and it did not hurt the plants. Some plants I gave away to keep my cats safe.