Plant cat grass seeds in soil about a quarter-inch deep, water them lightly, and keep them in a warm spot with indirect light for 7 to 10 days until they sprout

Cat grass grows fast and does not need much to get your free guide. You can plant seeds directly in potting soil, water them once, and see green shoots within a week. The whole process takes about three weeks from seed to a grass your cat can safely eat. Most people grow it indoors in a shallow container so they can move it away from other plants and refill it when the cat eats it down.

The two most common types are wheatgrass and oat grass. Both are safe for cats and taste similar to lawn. You can buy seeds at any garden center or online, usually in bulk packets that cost between $3 and $8 and will plant multiple containers.

Key Takeaways

  • Cat grass seeds need soil, water, warmth, and indirect light—they do not need fertilizer or special conditions to sprout.
  • Plant seeds a quarter-inch deep in moist soil, then water lightly every two to three days until sprouts appear in 7 to 10 days.
  • Move seedlings to a sunny windowsill once they sprout, and your cat can start nibbling in about three weeks.
  • Grow cat grass in a shallow, wide container so it is straightforward to refill when your cat eats it down.

What you need before you start

Gather a shallow container with drainage holes, potting soil, cat grass seeds, and water. A terracotta saucer, a low ceramic dish, or a recycled takeout container with holes poked in the bottom all work. The container does not need to be deep—cat grass has shallow roots and grows in just 2 to 3 inches of soil.

Fill the container with moist potting soil to about an inch below the rim. Do not use garden soil from outside; it can carry mold or pests. Potting soil is sterile and drains better. If your soil is dry, wet it with a spray bottle or by pouring water in until it feels like a wrung-out sponge.

Planting the seeds

Scatter the seeds across the soil surface and press them down gently with your hand or a flat object. They should sit on top of the soil or just barely covered. If you bury them deeper than a quarter-inch, they may not sprout. You can plant them thick—cat grass does not need space between seeds the way vegetables do.

Mist the soil with a spray bottle to settle the seeds without washing them away. The soil should stay moist but not soggy. Water every two to three days with a light spray, or whenever the top of the soil feels dry to your touch. Too much water causes mold; too little stops the seeds from sprouting.

Where to put the container while seeds sprout

Keep the container in a warm spot—between 60 and 75 degrees Fahrenheit is ideal. A kitchen counter, a shelf in a closet, or a bathroom away from direct sun all work during the sprouting phase. Cat grass does not need light to germinate, so you can cover the container loosely with a plastic bag or cloth to hold moisture in while the seeds wake up.

Check the soil every other day and remove the cover once you see the first green shoots, usually between day 7 and day 10. At that point, move the container to a sunny windowsill or under a grow light. The seedlings need bright light to grow thick and green instead of pale and spindly.

Moving seedlings to light

Once sprouts appear, place the container in the brightest spot you have—a south-facing or west-facing window is best. If your home does not get much natural light, a basic LED grow light on a timer for 12 to 14 hours a day works well. The grass will grow faster and stay greener with good light.

Keep watering lightly every two to three days. The soil should stay moist but never waterlogged. If water pools on the surface, you are watering too much. If the soil dries out completely, the grass will wilt, though it usually recovers after a drink.

When your cat can start eating it

Cat grass is safe to eat as soon as it is 3 to 4 inches tall, usually around day 14 to day 21. Your cat may start nibbling before then, and that is fine. The grass does not need to be a certain height to be safe—it just needs to be tall enough that your cat can grab it without eating soil.

Once your cat starts eating the grass down, it will regrow for a few weeks if you keep watering it. Eventually, the roots get tired and the container stops producing. When growth slows, pull out the old soil and plant a fresh batch. Most people keep two or three containers going at once so there is always fresh grass ready while one batch is being eaten.

Planting cat grass outdoors

If you have a small outdoor space your cat can access safely, you can plant cat grass directly in a garden bed or a large pot outside. Follow the same steps: scatter seeds on moist soil, keep the soil damp, and move the container to a sunny spot once sprouts appear. Outdoor grass grows faster because of stronger sunlight and warmer temperatures, but it is also exposed to rain, wind, and insects.

Plant outdoor cat grass in spring or early fall when temperatures are mild. In summer heat, the grass may dry out too quickly. In winter, it will not grow. If you live in a cold climate, stick with indoor growing, which you can do year-round.

Frequently Asked Questions

Can I plant cat grass seeds directly in my yard instead of a container?

Yes, but a container is easier to manage because you can move it away from other plants and refill it when your cat eats it down. If you plant it in the ground, your cat may eat surrounding plants too, and the grass will take longer to regrow. A container also keeps the grass away from pesticides or fertilizers you might use on the rest of the lawn.

How often should I water cat grass seeds?

Water every two to three days with a light mist or spray, or whenever the top of the soil feels dry. The soil should stay moist like a wrung-out sponge, not soggy. During the sprouting phase, you can cover the container to hold moisture in and water less often. Once sprouts appear, water more regularly because the grass uses more water as it grows.

What if my cat grass is pale or spindly?

It is not getting enough light. Move the container to a brighter window or place a grow light 6 to 12 inches above it. Pale grass is still safe to eat, but it will be weaker and may not regrow as well after your cat eats it. Better light also makes the grass taste better and grow faster.

Do I need to add fertilizer to cat grass?

No. Cat grass grows in potting soil that already has enough nutrients for a few weeks of growth. Fertilizer is not necessary and can make the soil too strong for such a short-lived plant. Just use fresh potting soil and water.

Why is my cat grass getting moldy?

The soil is too wet or the air is too humid. Water less often and make sure the container has drainage holes so excess water can escape. If mold appears, remove the affected soil and replant. Poor air circulation also causes mold, so keep the container in a spot with a little air movement—not in a sealed closet or under a plastic cover for too long.