By Jennifer Copley (Last Updated 8 January 2015)
Eating greenery is a natural behaviour. Experts believe that cats do this to help them get rid of hairballs, which could otherwise cause health problems, and to obtain folic acid, a required nutrient.
Most cats will choose grass if it’s available, but indoor cats without access to grass may take to snacking on house plants, particularly those with slender grass-like leaves such as spider plants and dragon trees. This worries many owners, as some plants are poisonous to cats. While the majority of houseplants cause relatively minor symptoms if ingested (usually mouth irritation and/or gastrointestinal upset), there are a few, such as lilies, that can be deadly.
There are a number of ways to deter cats from snacking on plants or using them as litter boxes. The first line of defense is to put plants out of reach, but this isn’t always possible. Other options include providing alternatives, using negative reinforcement, and making plants less appealing.
Given the option, cats usually prefer to snack on grass rather than houseplants. Providing a bit of cat grass in a flowerpot will deter most cats from eating houseplants, and praising the cat when she chews on the cat grass rather than a houseplant will help her to make the switch.
A little catnip grown indoors may also be appreciated. Catnip is safe for cats, and it’s not dangerously addictive, as many people believe.
Classical conditioning techniques are highly effective with cats. Purchasing a water gun and giving the cat a squirt every time she starts eating a houseplant may cause her to abandon the activity. However, given that cats do need a bit of greenery from time to time, driving them away from non-toxic houseplants is not recommended without first providing some cat grass as a substitute. Also, because this approach requires a lot of vigilance on the part of the owner, using a cat deterrent may be easier.
There are a number of ways to make houseplants unappealing to cats. There is a product called Sticky Paws tape that can be used specifically to protect plants without harming cats. Placing the abused plant on a piece of plastic carpet runner (pointy side up) is also a good deterrent.
A more high-tech solution is to purchase a motion-activated deterrent that emits a little burst of air, which will startle a cat but not cause any harm. One such product is the SSSCAT® cat repellent device. There are also odour-based repellents, but these are usually not as effective, and some may be toxic.
The leaves of plants can be made less tasty with the application of non-toxic substances. The ASPCA recommends products such as Grannick’s Bitter Apple® and Veterinarian’s Best® Bitter Cherry Spray.
Spraying a vinegar solution on plant leaves to make them smell bad to cats is also commonly recommended, but this may harm the plant. Using citrus oil or moth balls is also a bad idea, as these can have toxic effects. Another dangerous strategy is sprinkling hot chili powder on the plant, as pets may get it on their paws and then lick it off, burning their mouths. Also, putting anything that can poison or burn in an accessible place is extremely dangerous to children.
How to Prevent Cats from Digging in Plant Dirt
If a cat likes to dig around in plant dirt and use the plant pot as a litter box, covering the soil with stones can make the it less appealing, and this is an attractive alternative to covering the top of a large plant’s pot with ugly wire mesh. Some people have also had luck with placing citrus peels on the soil, though these must be replaced with fresh peels regularly to maintain their efficacy.
Creating a cover to place over the dirt is the most effective way to prevent digging. You can make your own using plastic or rubber. Thin rubber gym mats, which are available in a variety of attractive colours. They can be cut to fit the pot and their flexibility makes them easy to place around the plant’s stem. There are also plant dirt covers commercially available, such as Dirty Little Cover-Ups™, which come in a variety of designs including wood, pebble, and ivy.
For information about whether common plants you have in your home are cat-friendly or dangerous, see Plants That Are Poisonous to Cats and Dogs and Pet-Safe Plants. For tips on protecting outdoor plants without risking harm to people or animals, see How to Keep Cats Out of Gardens.
- ASPCA Virtual Pet Behaviorist. (2009). “Cats Who Eat Plants.” ASPCABehavior.org.
- David Suzuki Foundation. (2008). “Mothballs: They Smell Bad for a Reason.” DavidSuzuki.org.
- Drs. Foster & Smith, Veterinary & Aquatic Services Department. (2008). “Citrus Oil Toxicity in Cats and Dogs.” PetEducation.com.
- Tabor, Roger. (1997). Understanding Cat Behaviour. Cincinnati, OH: F&W Publications Inc.