Tips on growing and caring for cat grass?

I've tried window box gardening inside my apartment of catnip and cat grass. They grow beautifully, but after a week, they die off! I can't seem to keep them alive, and Monet enjoys fresh cat grass and catnip.

I've tried the stuff you buy at petstores, I've tried seeds from a nursery, and they all have the same result.

Anyone have suggestions on how to care for these plants for the kitties?

I guess it belongs here? if not, feel free to move it to right topic

I buy, every so often, a pot from the produce section of the grocery store. It is green and lush. It costs $2.99. After a couple weeks, from lack of sunlight where it is placed on the floor, and my cats nibbling on it, it looks yellow and tatty. I throw it out.

Sometimes I grow it from the tubs or packages you can buy at the pet food stores. But it costs more (!) and it is never as lush as the pre grown stuff from the grocery store.

I have a green thumb, but I don't think it is worth growing.

Robin

"Cat grass" is not intended to be long-lived. It's usually oats, rye, or wheat, and without the proper conditions to mature to seed-bearing, it will just fade and die. I usually have a new pot sprouting before the last one starts to fade. The secret to having it as lush as the store-bought stuff (after making sure you have the same kind of seed) is putting down a very thick layer of seed--no overcrowding concerns here!

The catnip should last longer, though. I don't have any tips because my only experience with it is throwing a pot of what I thought was dead catnip into the backyard, and it went wild! But I don't know how to make it happy indoors.

Indoors lack of light is a problem, even on a window sill, and so is too much heat and growing in small pots.  The larger the pot the easier it is to get the watering right - water when the surface is dry, drench well, let it drain.

A north-facing window sill (unless you are south of the equator!) is best, turn the pot regularly, and sow with grass which grows from the bottom and is OK with being regularly eaten.

It will get tall and lean towards the light if it's not got enough, and will eventually turn yellow.  If you have a yard you can grow it in (even in a pot) it will do much better.