Why Do Cats Eat Grass and Is It Safe?

Why do cats eat grass?

We don’t know for sure, and there is little research on the topic. Eating grass, and other plants occurs more frequently in younger animals. There are several possibilities as to why cats enjoy the occasional nibble of grass.

To help them vomit

We all know what happens after our cats consume grass; they come back inside and vomit all over the floor. Grass acts as an irritant to the stomach, and cats can’t digest grass in the way herbivores as they don’t have the necessary enzymes which can help the cat to rid the gastrointestinal tract of hairballs, indigestible animal parts such as feathers and beaks, something disagreeable and intestinal parasites.

Grass can help with the passage of hairballs

When cats groom themselves, they inevitably ingest fur which can build up in the stomach. Adding to the vomiting theory, another possible reason for grass consumption is to assist with the passage of hairballs out of the body either through vomiting or via the feces.

Grass acts as a laxative

The indigestible fibre adds bulk to the feces which makes them easier to pass out of the body which can help speed up the passage of feces.

It contains nutrients and micronutrients

In particular, cat grass contains folic acid (vitamin B9) an essential vitamin that performs several roles such as helping with the formation of hemoglobin and the synthesis and repair of DNA.

As we know, cats are carnivorous; they need to consume meat to survive. Dogs and humans can get by without meat. However, when cats hunt, they consume almost all parts of their prey which include the stomach and the stomach contents which often contain small amounts of plant matter and the nutrients such as folic acid

It’s enjoyable

It may be as simple as that. They enjoy the taste of grass. Having spoken to many cat-loving friends, it is no longer a surprise to hear of cats eating other types of greenery such as cucumber and broccoli. Read more on human foods cats can eat here.

What kind of grass can cats eat?

If you want to grow a tub of grass inside for your cat to nibble on, common types include:

  • Wheatgrass
  • Barley
  • Orchard Grass
  • Common oat

How to grow cat grass

Cat grass is easy to grow. Either buy a pot of cat grass or grow from seed. Place in a bright spot and water well. If you have access to seeds, add a teaspoon of seeds to the pot once a week and water well. This will keep your cat in grass indefinitely.

Better still, purchase a seedling tray from your local garden centre, this should not contain individual squares for each seed but a large rectangular tray, add potting mix and then seeds. Allow the grass to grow in full sun. This has the benefit of providing a cat with a grassy spot to sit as well as grass to nibble on, which is especially useful for indoor cats or those with access to an outdoor enclosure.

Is there a difference between cat grass and catnip?

Yes, catnip is a member of the mint family. They are completely unrelated. Catnip can also induce a high in some cats; however, cat grass doesn’t have this effect on cats.

Both cat grass and catnip are perfectly safe for your cat to eat but do bear in mind there are a large number of plants that are toxic to cats. It is recommended you don’t have indoor houseplants that are poisonous as they can in some cases lead to death.

Related: Plants toxic to cats

Safety precautions

Take care if the cat eats grass outside which may have been sprayed with chemicals such as weed killers or fertilisers that are toxic to cats.


  • Julia Wilson, 'Cat World' Founder

    Julia Wilson is the founder of Cat-World, and has researched and written over 1,000 articles about cats. She is a cat expert with over 20 years of experience writing about a wide range of cat topics, with a special interest in cat health, welfare and preventative care. Julia lives in Sydney with her family, four cats and two dogs. Full author bio