Cat grass is one of the few houseplant-adjacent products that almost every cat household benefits from, and the one most cat owners get wrong by assuming it’s a single species. It isn’t. The “cat grass” sold in kits at pet stores is a mix of cereal grasses, usually some combination of oat, wheat, barley, and rye, that cats can safely chew. Knowing which species are in your kit, why your cat is drawn to grass in the first place, and how to use grass as a redirect for your cat’s interest in your other houseplants is the difference between a tray that gets ignored and one that actually solves problems.

Quick answer

Cat grass is a mix of cereal grasses, most commonly oat grass (Avena sativa), wheat (Triticum aestivum), barley (Hordeum vulgare), and rye (Secale cereale). A typical commercial cat-grass kit contains a blend of two or three of these. The ASPCA classifies all four species as non-toxic to cats and dogs.

Cats eat grass for several reasons: to help pass hairballs, to add fiber to their diet, and possibly out of an evolutionary instinct inherited from wild cats. A cat with regular access to grass is significantly less likely to chew on your houseplants, which is the single best reason to grow some.

Growing it is easy: seeds, soil, light, water, 10 days. The rest of this guide covers the species options in detail, the behavior reasons, the step-by-step growing process, and how to use cat grass as a redirect for cats who like to chew houseplants they shouldn’t.

What cat grass actually is

“Cat grass” is a category, not a species. When you buy a tray at the pet store or a starter kit online, you are usually getting one of these four cereal grasses, or a blend of them.

Oat grass (Avena sativa) is the most common single species in commercial cat-grass kits. Oats sprout fast (3 to 5 days), grow to a chewable height (4 to 6 inches) within about 10 days, and tolerate the rough treatment cats give them. The blades are slightly thicker and a deeper green than wheatgrass. Most cats accept oat grass readily.

Wheat (Triticum aestivum, sold as “wheatgrass”) is the same species you see at juice bars for human wheatgrass shots. It sprouts in about 4 to 7 days, grows quickly, and has a slightly sweeter flavor than oat grass. Many cats prefer wheat to oat, but wheat trays are more delicate and get destroyed faster.

Barley (Hordeum vulgare) sprouts in 4 to 7 days and produces a slightly tougher blade. Less common as a standalone cat grass; more common in blends.

Rye (Secale cereale) sprouts in 4 to 7 days and has the longest, narrowest blades. Often used in seed mixes to add texture variety.

The “cat grass mix” you buy at most pet stores is typically oat + wheat or oat + barley + rye. Single-species options exist if you want to test what your cat prefers.

A note on naming confusion: some sources call orchard grass (Dactylis glomerata) a “cat grass.” It is also non-toxic, but it is a perennial pasture grass rather than a cereal grass and is less commonly grown indoors. If a kit lists “cat grass” without specifying the species, you can almost always assume it’s the cereal blend, not orchard grass.

Why cats eat grass

The behavior is well-documented and there is more than one reason. Veterinary research suggests several non-exclusive explanations, and a single cat may eat grass for several of them at different times.

Hairball management. Grass blades are slightly abrasive in the stomach, and grass fiber can help cats either pass hairballs through the digestive tract or vomit them up. Vomiting after eating grass is so common that many cat owners assume the cat eats grass to vomit. The vet consensus is more nuanced: grass-eating sometimes induces vomiting, sometimes doesn’t, and is probably both a fiber strategy and a hairball strategy depending on the cat.

Fiber. Cats are obligate carnivores but still benefit from small amounts of plant fiber. Cat grass adds roughage in a way that’s safe and self-regulating.

Evolutionary instinct. Wild cats are observed eating grass, and one widely cited theory is that grass-eating helps expel intestinal parasites. Whether this is genuinely the driver in domestic cats or just an inherited behavior is debated, but the instinct itself appears to be real.

Micronutrients. Cereal grasses contain small amounts of folic acid and other B vitamins that may benefit cats in small doses. The evidence here is weaker than the hairball/fiber evidence, but the harm is nil so the theory persists.

Just liking it. Some cats simply enjoy the texture. The behavior reinforces itself, and a cat that’s developed a grass habit will look for grass even when none of the above are driving them.

Roughly 70 percent of cats with regular grass access will chew it. The other 30 percent are uninterested no matter what you offer. This is similar to the catnip-response distribution (about 70 percent of cats respond to catnip; the response is genetic). Whether the cat-grass non-responders are genetically distinct or just learned-uninterested is unclear.

How to grow cat grass at home (step by step)

Growing cat grass from seed is one of the easiest indoor gardening projects there is. From start to chewable tray takes about 10 days.

What you need:

  • Cereal grass seeds (oat, wheat, barley, rye, or a blend). A 1-pound bag costs $5 to $10 on Amazon and grows 8 to 12 trays.
  • A shallow tray or pot, 4 to 8 inches across. Drainage holes preferred but not essential.
  • Potting soil or coconut coir (about 2 inches deep in the tray).
  • A spray bottle for watering.
  • Indirect light. A windowsill works; direct sun for a few hours a day is fine.

Step 1 (Day 0): Pre-soak the seeds. Cover the seeds with water and let them sit overnight. This is optional but speeds up germination by a day or two.

Step 2 (Day 1): Plant. Spread the seeds in a single layer across the soil surface, they can touch, but try to avoid heavy clumping. Press the seeds gently into the soil so they make contact. Cover lightly with a thin layer of soil (about 1/4 inch) or leave them on the surface; both work.

Step 3 (Days 1 to 5): Keep moist. Mist with the spray bottle once or twice a day to keep the soil damp but not waterlogged. If you over-water, you’ll get mold rather than grass.

Step 4 (Days 3 to 7): Sprouting. Tiny white roots appear first, then green shoots. The first few days look unimpressive; by day 5 you’ll see a clear lawn forming.

Step 5 (Days 7 to 14): Growing. The blades grow about 1/2 inch per day once they’re up. Most cats will be interested when the blades are 3 to 4 inches tall.

Step 6 (Day 10 onward): Offer to your cat. Place the tray somewhere accessible to your cat. Watch them. Some cats dive in immediately; others investigate for a day or two before chewing.

A single tray typically provides good chewing for 2 to 3 weeks before the grass starts to yellow and decline. At that point, compost it (or just throw it out) and plant a new one. Many people stagger two trays so there’s always a fresh one available.

If you would rather skip the growing process, commercial cat-grass kits are widely available on Amazon, Chewy, and at most pet stores. A kit typically includes a small pot, soil disc, and a packet of seeds, runs $8 to $15, and produces one tray. They’re convenient but more expensive per tray than buying bulk seeds.

Cat grass vs. catnip vs. wheatgrass

These three get confused constantly. They are not the same thing.

Cat grass is the cereal-grass category described above. Cats chew it. It produces no behavioral effect beyond the chewing satisfaction and any digestive consequences.

Catnip (Nepeta cataria) is an herb in the mint family. Cats respond to its active compound, nepetalactone, with rolling, drooling, vocalizing, and a brief period of excited behavior. About 70 percent of cats respond to catnip (it’s genetic). Cats don’t typically eat catnip in volume; they sniff it, rub on it, and may chew a leaf or two. It is not a chewing plant.

Wheatgrass is one specific cereal grass (Triticum aestivum) that humans drink as a juice. It is also one of the most common species in commercial cat-grass kits. So wheatgrass is a type of cat grass, but cat grass is broader.

If you want chewing satisfaction and a redirect from houseplants → cat grass. If you want a sensory toy that your cat plays with → catnip. If you want what you see at the juice bar → that’s wheatgrass, which doubles as cat grass.

A cat household can reasonably have both cat grass and catnip going at once; they serve different needs.

Using cat grass as a houseplant redirect

This is the part that matters if you’re growing cat grass because your cat won’t leave your houseplants alone. The honest answer: cat grass works, but it works better as part of a system, not a magic bullet.

What the redirect actually does: it gives your cat a designated, legal, chewable target. A cat with regular access to fresh cat grass is significantly less likely to seek out your other plants for chewing. The behavior pathway from “I want to chew something green” to “the spider plant on the shelf” gets interrupted by “there is grass right here.”

How to set it up for maximum effect:

Place the grass where your cat already hangs out. If your cat sleeps on a specific windowsill, put the grass there. Don’t make them find it.

Keep the grass fresh. A dying yellowing tray is less appealing than a fresh green one. Replant before the previous tray is fully exhausted. Cats notice quality.

Combine with placement of your other plants. Cat grass redirects the behavior, but if your pothos or peace lily is sitting on a low shelf within easy reach, your cat may still chew it occasionally. Move toxic plants to genuinely out-of-reach spots (hanging at 6+ feet, no nearby launching surfaces) and use cat grass to satisfy the chewing urge.

Watch for the introduction period. Some cats accept cat grass immediately. Others take a few days to investigate before they start chewing. Don’t conclude that “my cat doesn’t like cat grass” after one day; give it a week.

The strongest case for cat grass is for cats that show interest in your toxic plants. If your cat ignores your plants completely, cat grass is optional and probably just becomes a cute photo opportunity. If your cat chews everything green within reach, cat grass is the single best behavior change you can make.

For the full list of plants that are safe vs. toxic in cat households, see our cat-safe houseplants pillar guide.

How much cat grass is too much?

Most cats self-regulate. They chew a few blades, walk away, come back later, chew a few more. No single-session limits apply.

The exception is the cat who treats a fresh tray as an all-you-can-eat buffet. A cat that eats half a tray in one sitting will likely vomit it back up, partially digested grass blades, often the same evening. This is uncomfortable for the cat and (more practically) annoying for whoever cleans it up. It is not dangerous.

If your cat is a binge-chewer:

  • Offer the tray in shorter sessions. Take it away after 15 to 20 minutes of grazing, then offer it again a few hours later.
  • Try a smaller tray. A 4-inch pot is harder to over-eat than an 8-inch tray.
  • Watch for satiety cues. A cat that walks away from the tray on their own usually self-regulates fine; a cat that keeps coming back until they vomit needs you to limit access.

Cat grass kits vs. growing from seed

Both work. Choose based on what you value:

Kits are convenient. Open the box, follow the instructions, water, wait 10 days. Most kits cost $8 to $15 for a single tray. Brands like SmartCat, The Cat Ladies, Pet Greens, and ZestiGreens are widely available on Amazon.

Seeds + soil are cheaper long-term. A $5 to $10 bag of oat or wheat seeds grows 8 to 12 trays. A reusable shallow tray and a bag of potting soil rounds out the kit. Cost per tray drops to roughly $1.

My recommendation: start with a kit to confirm your cat is interested, then buy bulk seeds and reuse a tray once you know it works. The first kit is a low-friction test; the bulk seeds are the actual long-term solution.

A note on indoor seed sources: cereal grass seeds sold as “cat grass” are typically untreated (no pesticides or anti-fungal coatings). Seeds sold at garden centers for outdoor lawn use can have coatings that aren’t safe for indoor consumption. Buy seeds labeled specifically for cat grass or sprouting/juicing, not for outdoor planting.

Where to place cat grass for best results

A few practical placement notes:

Bright indirect light. Most cereal grasses tolerate a wide range of light, but they grow leggier and weaker in deep shade. A north-facing windowsill is fine; a south-facing one is better. Direct hot afternoon sun for hours is too much (the grass dries out).

Somewhere your cat naturally visits. If your cat ignores the bathroom, don’t grow cat grass in the bathroom. Look at where your cat already spends time and put the tray there.

On a stable surface. Cats sometimes step in the tray, which is fine, but a tray that tips over scatters wet soil. Choose a surface where a wobble won’t matter.

Away from your other plants. Counterintuitive, but worth doing. Placing cat grass next to a houseplant they used to chew sometimes confuses the redirect signal. Put the cat grass somewhere distinct, and put the toxic plants somewhere they cannot reach.

Is cat grass safe for dogs?

Yes, for the same reasons. The same cereal grasses (oat, wheat, barley, rye) are non-toxic to dogs per the ASPCA, and dogs sometimes eat grass for similar reasons (fiber, instinct, hairballs-equivalent, just because). Some commercial kits are marketed specifically for cats but work equally well for dogs.

The practical difference: dogs are larger and may eat the entire tray in a sitting. If your dog is the type, treat cat grass like any other edible houseplant, supervise, and don’t be surprised if the tray needs replanting weekly.

A note on lawn grass: the grass in your yard is not necessarily safe for dogs in the same way cat grass is. Outdoor lawn grass may be treated with pesticides, herbicides, or fertilizers that are not pet-safe. Cat grass grown indoors from untreated cereal seeds is the safe version of “grass for pets.”

FAQ

What is cat grass made of? A mix of edible cereal grasses, most commonly oat grass, wheat, barley, and rye. All four are non-toxic to cats and dogs per the ASPCA. Commercial kits typically blend two or three of these.

Why do cats eat grass? Several reasons documented in veterinary research: to help pass hairballs, to add fiber, possibly to expel parasites (an instinct inherited from wild cats), and because chewing is satisfying. About 70 percent of cats with grass access will chew it.

Is cat grass the same as wheatgrass? Wheatgrass is one of the species commonly used as cat grass, so yes, wheatgrass is a type of cat grass. Cat grass as a category is broader and includes oat, wheat, barley, and rye.

Is cat grass the same as catnip? No. Cat grass is for chewing. Catnip (Nepeta cataria) is an herb in the mint family that produces a behavioral response. They serve different needs.

How do I grow cat grass at home? Spread cereal grass seeds on moist potting soil, keep damp, place in indirect light. Seeds sprout in 3 to 7 days; tray reaches chewing height in 10 to 14 days. One tray lasts 2 to 3 weeks.

How much cat grass is too much? Most cats self-regulate. A cat that eats half a tray in one sitting will probably vomit it back up, which is harmless but unpleasant. Take the tray away if your cat is a binge-chewer and offer it back later.

Will cat grass stop my cat from chewing my houseplants? It significantly reduces the behavior for most cats, but it works best as part of a system that also includes placing your toxic plants well out of reach. Cat grass alone is not a guarantee; cat grass + smart placement is.

Is cat grass safe for kittens? Yes. Kittens older than about 8 weeks can interact with cat grass safely. Younger kittens are still getting most of their needs from their mother’s milk and don’t need it, but a small amount is harmless.

Sources and further reading

If you’re growing cat grass for the first time, start with a kit, see if your cat is interested, and graduate to bulk seeds once you know they like it. The hardest part is remembering to plant the next tray before the current one runs out.