Where the Green Grass Grows: Grass Treats for Cats

By Lynn Buzhardt, DVM

Cats can be finicky eaters so cat owners work hard to provide just the right food to please the most discriminating feline palate. Wet or dry? Tuna or chicken? Chunks or morsels? The options can be overwhelming. Yet amid all the pet food choices there is one more dietary option for your cat…grass!

Why grass?

Today’s cats are sophisticated creatures, but they still possess the basic characteristics of their feral ancestors. Cats are predominantly meat eaters; however, their digestive systems are also adapted to process grass. Why?

In the wild cats stalk and hunt for food. After consuming their prey (often small mammals or birds) they may nibble a little grass. One theory is that eating grass makes the cats throw up the less digestible parts of their protein rich meal (hair, bones, or feathers).

Another theory is that eating grass has health benefits. Grass is a source of needed trace minerals, micronutrients, and vitamins A, B, and D. Grass also contains folic acid which impacts the production of hemoglobin, an important component of blood oxygenation. Moreover, grass contains chlorophyll which may aid minor medical problems. Chlorophyll may have helped cats deal with infection and pain before the advent of modern day antibiotics and anti-inflammatory drugs.

Today, most cats are cared for by people who feed them an ample quantity of a nutritionally balanced diet, so they lack nothing. Even so, cats still like to graze on grass. Good for them! Grass benefits even well-fed cats. Grass provides roughage that aids digestion and elimination. Cats that eat grass routinely may have more regular gastrointestinal tracts, fewer hair balls, and less constipation. Plus the chlorophyll in grass helps keep a cat’s breath fresh! Finally, some cats simply like chewing grass! It can be entertaining!

How much grass is appropriate?

The grass may be greener on the other side of the fence, but just how much grass should a cat eat when she gets there? As usual, moderation is key!

Cats don’t have the necessary digestive enzymes to process large quantities of grass and overeating can result in excess vomiting. On the opposite side of the digestive coin, if the cat doesn’t throw up the green turf, the insoluble fiber in grass can potentially build up and cause an intestinal blockage. So how much grass is advised?  Here’s a good rule of thumb: Treats of any variety, including grass, should comprise no more than 10% of a cat’s total caloric intake.

What kind of grass is the best?

Outdoor cats may graze on a variety of grasses, while indoor cats depend on their owners for grassy snacks. So what type of grass should you plant? First, let’s make a quick distinction. Grass and catnip are not the same thing. Catnip is a member of the mint family.

Cat grass usually refers to grass that produces cereal grains such as oat, wheat, barley, alfalfa, and rye. You can start with one variety or plant a couple of different grasses and assess your cat’s preference. You can also consider which variety grows best in your particular home with your personal green, or not-so-green, thumb.

How do you grow cat grass?

Even if you aren’t a master gardener, you can probably grow enough grass to keep your cat happy. Here are a few tips to help you with your indoor kitty garden.

  • Choose a relatively shallow container with drainage openings. Heavier containers are better because they are less likely to tip over when your cat paws at the grass or tries to walk on the 'indoor lawn'. Purchase regular potting soil. Look for grass seeds online or at a local nursery or pet store.
  • Water-soaked vs. dry seeds. Some people advise soaking grass seeds before planting, but many gardeners plant seeds directly from the packet. Regardless of your preference prior to planting, it is important to keep newly planted seeds constantly damp for several days.
  • Fill the container ¾ full with potting soil. Sprinkle seeds evenly on the surface. Then cover the seeds with ¼ inch of potting soil and water with a spray bottle. Cover the container loosely with plastic wrap and keep it at room temperature out of direct sunlight until the seeds sprout. Green sprouts should emerge within 3-7 days.
  • Once seeds spout, remove the plastic wrap and move the container to a location that receives direct sunlight. Water sparingly to keep the soil damp but not wet. Too much water may precipitate the growth of mold and ruin your garden. Place your finger on the soil and re-water when it feels dry to the touch. The grass should be ready to eat within 10-14 days or when it reaches a height of about 4 inches (10 cm). The crop of grass should last up to three weeks providing your cat with lots of snacks and fun!
  • When the grass wilts or turns yellow, pull out the dying shoots. You may plant more seeds in the same container or plant a whole new batch. If your cat really enjoys the grass, you may plant several pots about a week apart and rotate them to provide a constant source of fresh grass.

If you’d like to streamline your efforts, you may purchase a complete grass growing kit with everything you need, including detailed instructions.


Not all green things are good for your cat. Some plants are poisonous. Unfortunately, kitties are not horticulturists and they may not be able to distinguish between safe and dangerous plants.

If your cat is accustomed to eating grass, she may assume that she can snack on anything green such as the toxic rhododendron on the window sill or the poisonous tiger lily on the sun porch. Keep dangerous plants out of reach in case your cat decides to expand her palate from grass to harmful plants.

Another possible danger posed by cat grass is the presence of mold. Ingestion of mold will challenge the digestive tract and can be toxic. If your grass begins to look sickly, remove the planter and cultivate a new batch.

Here’s another warning. If your cat eats grass indoors, he may nibble the lawn if he goes outside. Eating outdoor grass can be harmful if it has been treated with pesticides. In addition, intestinal parasite eggs often survive in soil for long periods of time. Fortunately, most cats just nibble the top of the grass, but if your cat grazes down to the roots and consumes a little dirt along with her greens, she can become infected with intestinal parasites.

To Graze or Not to Graze

Is eating grass a healthy dietary option that should be a long term addition to your cat’s nutritional plan? Will your cat’s diet be nutritionally sound if you don’t plant an indoor grass garden? Are you already overwhelmed with the age old job of keeping your cat happy?

If you have questions about feeding your cat grass, talk to your veterinarian. With your cat’s overall medical status in mind, your veterinarian can give you sound advice on the pros and cons of adding grass to your kitty’s diet.

And if you decide not to grow an indoor grass garden, don’t feel guilty. After all, the grass isn’t always greener...

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