There are plants that are dangerous to some cats. If you have a houseplant that you are not sure about, consult your vet to know if it is safe for cats. Here is a list of a few plants that are dangerous to cats.
1. Crocus
2. Hyacinth
3. Lilies
4. Arrowgrass
5. Aloe Vera
6. Boxwood
7. Almond
8. Apple
9. Avocado
10. Apricot
11. Poinsettia (Maybe)
If you realize that your cat is going more and more towards dangerous plants, a good idea is to put orange peels in the plants dirt pot. Cats HATE the smell of orange, and will stay away. The odd thing is though, that some cats don't mind the smell of orange at all. Mirabelle loves the smell of orange. In that case, put something else that your cat hates the smell of, no NOT fecees, but nothing like a dangerous plant either.
If you see your cat nibbling on catnip or grass, it's OK! Cats LOVE catnip. Experts say that cats eat grass to vomit, getting rid of any fur they may have swallowed. Some plants (besides catnip and grass) are OK for your cat to eat too!