After working tirelessly to landscape your yard and make your outdoor space a beautiful sanctuary, you don't want to see it destroyed by neighborhood dogs or cats who scratch and sniff where they don't belong. If you want to keep your special place a dog-free zone, there are some plants that will dissuade canine visitors.
Plants toxic to dogs
While there are some plants that repel dogs, there are also some plants that are toxic to dogs. Whatever you choose to plant in your garden, take care to make sure you don't landscape with plants that may be toxic to pets. The American Society for the Prevention of Cruelty to Animals maintains a list of plants that are toxic to dogs.
Plants that repel dogs
If you just want to keep dogs from getting too curious about your garden, consider things you can add to your garden such as mulch. Garden Guides says that dogs don't like to walk on mulches or ground covers that would be irritating. Chunky pine cones, thorny plant clippings such as those from rose or blackberry, or other uncomfortable mulches such as large wood chips will deter dogs. They also say to keep sand to a minimum as this is something that dogs actually enjoy digging in.
Prickly plants such as aloe, agave, prickly pear, hollies, barberries, and huckleberry are plants that deter dogs and cats and that can be used as borders around garden areas to physically block access. Dogs don't enjoy strong odors such as garlic, onion, or citrus. Garden Guides suggests mixing citrus peels into your mulch to provide an extra scent barrier.
SF Gate lists several plants that deter dogs and cats. To provide an added bonus, some of these plants also repel mosquitoes!
While Rue is an attractive shrub with blue-green foliage, its odor is enough to keep dogs and cats away. SF Gate says cats do not like the feel of the plant. Reader's Digest says that planting one rue plant next to each of your tomato plants will keep the dogs away as well as ants. One note of caution though is that rue (Ruta graveolens) is toxic to humans, especially to children.
Coleus canina, also known as Scaredy Cat plant according to SF Gate, is said to have an odor that repels both cats and dogs, although humans won't notice it unless they rub against it or crush the leaves.
The classic mosquito-repelling plant also repels cats as well as dogs. SF Gate says citronella oil is useful as a spray for areas where you don't want your dogs to go, even if you can't plant citronella — the oil comes from lemon grass, which only grows in the United States' hottest regions.
Since trees take such a long time to grow, planting them may not solve your immediate problem of looking for plants dogs won't destroy, says SF Gate. But over the long-term, citrus trees will provide not only a beautiful tree but also a delicious crop. Consider, instead, spraying citrus oil around your garden, or using citrus peels where you don't want your dogs to go.
Other ways to repel dogs
While there are a lot of plants dogs won't destroy, depending on the location and type of garden you have (or want) some plants might not work for you. Or they may take so long to grow that you need to look for a different, more immediate solution. If that's the case, Reader's Digest suggests fencing off the problematic area with wire fencing or an attractive picket fence.
They also suggest using a sprinkler. Automatic sprinklers are available that detect movement and turn on, providing a surprising spray to unwanted garden visitors, including dogs, cats, rabbits, deer, or any other critter that may eat your plants or otherwise disturb your oasis.