This method relies on the concept of light reflection which is said to scare cats away. Look for a few empty plastic bottles and fill them with red-coloured liquid or even just plain water. Place the bottles in areas that are exposed to light.
Citrus: orange, lemon, lime, and grapefruit
Citrus smells are widely reported as being repugnant to cats. You can use this to your advantage by throwing orange peels around your garden to keep cats away or spritzing a citrus scent on indoor fabric that you don't want your cat scratching up.
It is a common myth that cats are scared of water. This isn't actually true at all and some cats love the opportunity to stretch their sea legs and will eagerly jump in voluntarily. It's less of a fear, and more of an aversion. Cats are actually natural born swimmers.
Place half full bottles of water in boarders around the area you are trying to deter cats from entering. The light reflection deters cats. CDs can be threaded on string with knots to keep them apart. String these across flower beds or hang in trees.
Orange and lemon peels (cats dislike citrus smells), cayenne pepper, coffee grounds, pipe tobacco, lavender oil, lemon grass oil, citronella oil, peppermint oil, eucalyptus oil, & mustard oil.
Citrus or lemon scents (orange peels, lemon peels), garlic, ammonia, vinegar, coffee grinds, pipe tobacco, mustard, citronella, or eucalyptus all deter cats as well.
Vinegar as a cat repellent
Spraying Outdoors – Straight or diluted vinegar can be sprayed around the edges of a garden, and on plants, fences, posts and garden décor to keep cats away. Concentrate the spray on areas that the cats frequent or that you particularly want to protect.
Home-made Cat Deterrent Spray
2 cups white vinegar, 1 tablespoon whole cloves, 2 or 3 garlic cloves - peeled and crushed, 2 or 3 hot chillies, 2 or 3 drops of concentrated dish washing liquid, black pepper, water to fill bottle. Combine all ingredients in an empty two litre bottle, and leave mixture overnight.
Quick Solutions: Scatter fresh orange and lemon peels or spray with citrus scented fragrances. Coffee grounds, vinegar, pipe tobacco, oil of lavender, lemongrass, citronella or eucalyptus also deter cats. Plant the herb rue to repel cats, or sprinkle dried rue over the garden.
Spraying cats with water from a squirt bottle is not a reinforcement; it's a punishment. Giving your cat a choice of ways to express his behavioral needs and then rewarding his use of the choice you prefer is the best way to encourage your cat's “good” behavior.
Why Are Cats Afraid of Water? Cats hate water as they understand their environment through their nose and getting wet can remove their personal scent. They can also notice chemicals in the water that humans cannot sense.
As a general rule, cats are sensitive when it comes to smells, but there are a few scents they hate that might just surprise you. They can't stand citrus and as much as you might love the smell of fresh herbs, cats hate rosemary and thyme. Banana and mustard are a big no-no too, as well as lavender and eucalyptus.
Mix together lemon juice, rosemary and white vinegar - three things cats detest. Put the liquid in a spray bottle so it's easy to use around the garden. Simply spray near where the cats spend time - on planters, the patio, or even inside.
When used to clean an area previously sprayed by a cat, Nature's Miracle® No More Spraying eliminates existing stains & odors leaving behind lemon grass and cinnamon scents. These scents repel and prevent cats from returning to the area.
Texture: Sticky paper, aluminum foil, heavy plastic or a plastic carpet runner (knubby side up) can be placed in areas you want to be off limits. Cats hate walking on these surfaces.
Most recommended: Water: Cats hate it, so keep a water pistol (Super Soaker) handy and spray any time you see them in your yard. A spray with the hose also works well. Scarecrow Motion Activitated Sprinklers: The “Scarecrow” senses animals the same way security lights detect people; movement and heat.
Build an enclosed catio
To prevent your cat from crossing paths with the other cat, you could completely enclose your garden with wire fencing to keep the other cat out. This may not be possible for everyone, so you could instead create a smaller enclosure within your garden that your outdoor cat can use.
Council can issue an order to stop your cat trespassing and if you don't comply you can be fined. Some Councils require cats to be confined to their owner's property during certain hours.
Try orange and lemon peels, cayenne pepper, coffee grounds, lavender oil, lemon grass oil, citronella oil, peppermint oil, eucalyptus oil, and mustard oil. You can either sprinkle drops directly onto your flower beds or soak a cotton wool around it and place at entry points.
Cats dislike the smell of rue, lavender and pennyroyal, Coleus canina and lemon thyme. Plant a few of these throughout the garden. (Interplanting can attract pollinators and other beneficial insects too.) Cats steer clear of strong citrus scents.
Cats are incredibly sensitive to smell so strong scents such as lavender, peppermint or cinnamon are great for keeping them away. Choose one of these scents, mix it with water and spray it around the garden. While this is just a short-term option, it's cost-effective and non-toxic.
Adding 1 teaspoon of ACV to your pet's daily drinking water will increase their body pH. This will help prevent bacteria and yeast infections. Its anti-bacterial and disinfectant properties make Apple Cider Vinegar a powerful antiseptic and anti-inflammatory agent.
Coffee Grounds
The strong smell of coffee can be enough to keep cats off of your garden. Simply take your fresh, wet coffee grounds and distribute them around your borders and plants where you want to discourage feline attention.
Most cats find the pungent smell of vinegar to be overwhelming and flee the area. Most cats have an acute sense of smell and are discouraged by new, foreign, and powerful aromas. Vinegar for a cat repellent can be a humane, simple, and non-toxic solution.