CAT GRASS IS THE PLANT SAVER! More people need to know about this. Buy the seed kits and not the already growing grass, the seed gives you 3-4 pots worth of grass compared to one shot with the ready-grown pots. Here's what I do:
Using a shallow undrained take along food container I put two or three handfuls of potting soil in it soak it real good (not quite mud but evenly moist). Then sprinkle seeds across the surface not too densely then another handful of dry potting soil just covering over the seeds and lightly press it down, the dry soil soaks up moisture around the seed. Then I set the pot ontop of the microwave where it's warm and dark. If I plant the seed on Sunday they are usually germinated by Tuesday, then I put them near the terrarium lights until Thursday or Friday when they are 2-3 inches tall which is when I let the cats have at it, and they both love it and leave the other plants alone. I water when the grass gets weepy and very lightweight food containers are clear so you can see how wet or dry they are. My cats don't like it if it's too tall so I keep it trimmed to 4" high or so.
I have a little tuxedo cat who loves to find a perch and give his "death glare" at the female calico just to hear her howl and give her groan. I can spray him until I've emptied the bottle - he doesn't care! "Eh it's only water - I've been wet before, it more fun to hear her wail!"Cats really don't like spray bottles.