Wash a 4- to 6-inch growing pot with warm and soapy water to remove any dangerous bacteria. Rinse the pot with one-part bleach and nine-parts of water and allow it to dry completely.
Fill the growing pot with high quality soil, but leave 1 inch of space between the soil and the top of the pot.
Spread 2 tablespoons of cat grass seeds over the soil surface. Cover the seeds with 1/4 inch of potting soil.
Spray the surface of the soil with water to prevent disrupting the seeds. Continue to water the cat grass to keep the soil moist.
Sit the cat grass outdoors in an area where it will receive six hours of sunlight. You can also grow the potted grass indoors by placing it next to an east or south-facing window.
Place the cat grass in a location where the cat can reach it once the grass reaches 2 inches tall.