Dog Gone or Scaredy Cat (Plectranthus neochilus)
Do you have any recommendations for plants that repel dogs or do you have a suggestion for something to sprinkle on the lawn that would be helpful to the lawn but repellent (but of course not harmful) to pets?
Lisa Lunderman, Northridge
Your email brought to mind a certain Yeshiva, or Torah academy, located in Jerusalem, Israel’s capital city. Outside this Yeshiva is a large planter of Plectranthus neochilus, a ground cover species that has playfully been given the names of Dog Gone and Scaredy Cat on account of its ability to repel dogs and cats. There are even reports that in South Africa, its country of origin, this plant repels snakes.
Jerusalem is known for its feral cats. You see them everywhere. Although I never saw a cat in the Yeshiva’s Scaredy Cat planter, I cannot vouch for Scaredy Cat’s dog repellent properties. What I can promise you is that, once established, you will never have to water this plant. Its foliage is succulent, leathery, and fuzzy. Succulence and leatheriness insure that water is barely lost through trasnspiration while fuzziness means that a soft layer of botanical fur keeps leaf temperature cool, further reducing water loss.
Incidentally, if you do visit Jerusalem, and want to personally experience Dog Gone / Scaredy Cat, which is a powerfully pungent member of the mint family, you will find it at the Machon Meir Yeshiva in the neighborhood of Kiryat Moshe, not far from the city’s central bus terminal. Locally, Dog Gone is cultivated by San Marcos Growers, a supplier of many nurseries throughout Los Angeles and the Valley. This plant is sometimes sold under fictitious names with no botanical standing, such as Plectranthus caninus or Coleus caninus, as a means of promoting its capacity to deter canine creatures. It does not grow more than six inches tall and bears lavender blue flowers in all four seasons.
lucky nut (Thevetia peruviana)
Believe it or not, there is an entire plant family named for its members’ supposed capacity to keep dogs away. Apocynaceae (derived from the Greek apo, meaning “away from” and kyon, meaning dog) is a collection of plants known as the dogbane family, an indication that its members are the bane or ruin of canine creatures. Many poisonous plants are included in this family, including oleander (Nerium oleander) and lucky nut (Thevetia peruviana), but star jasmine (Tracehlospermum jasminoides), natal plum (Carissa spp.), frangipani (Plumeria spp.) and the Vinca ground covers are also dogbanes. What dogbanes share in common are pinwheel flowers and milky white sap. The baobab tree (Adansonia digitata) is one of the most famous dogbanes, as it plays an important role – that of unchecked evil — in “The Little Prince,” a classic children’s book by Antoine de Saint-Exupery. Whether these plants actually repel dogs, or are simply toxic to them when eaten (which is what I strongly suspect), is an open question. I can only assure you that dogs are smart enough not eat any of these plants voluntarily so that, if you plant them, you need not worry that you will cause any harm to your canine pets.
Amaryllis (Hippeastrum sp.)
A number of bulbs, including Amaryllis, Hippeastrum, and Narcisssus. are mentioned as being repellent to dogs. Rue (Ruta graveolens) is a member of the citrus family and, not only known as a dog repellent, has an odor so strong that is was classified in the Middle Ages as a strewing herb, meaning that it was effective at keeping demonic entities at bay. You should be able to find rue in the herb section of any well-stocked nursery or garden center. Garlic and onions are also touted as dog repellent plants and, last but not least, cacti and other spiny plants present an effective barrier to dogs. I remember one yard that was a haven for dogs until Bougainvillea ‘Raspberry Ice’ was planted around it. This variegated shrub with cream and green foliage, in addition to its raspberry colored bracts, was a deterrent to dogs on account of its spiny stems.
Having mentioned plants with ostensibly dog repellent properties, it is important to note that this deterrence is strictly anecdotal, meaning that no scientific study has every proven, conclusively, that certain plants keep certain animals – be they dogs, cats, deer, or gophers – away.
Curiously enough, dogs are demonstrably averse to the smell of citrus. Products such as Get Away take advantage of this fact by incorporating strong citrus essences into their spray and granular products. The problem with all pet or critter repellent products is that they break down when moistened, whether the moistening agent is rain or sprinkler spray. There are many other products, especially those containing black or cayenne pepper, that will keep away cats and dogs for a limited period of time. How often do you need to re-apply such products? Visit the area where you sprayed and sniff. If citrus or pepper aromas are still present, nothing needs to be done but, as soon as these aromas dissipate, it’s time to re-apply.
Correction: Several weeks ago, I wrote that Carol Bornstein, director of the Natural History Museum gardens in downtown Los Angeles, had discovered a new plant species. In fact, she had discovered a prostrate variety, dubbed ‘Silver Carpet,’ or ‘Silver Carpet Beach Aster,’ of an existing species, Lessingia filaginifolia, that typically grows upright. ‘Silver Carpet’ has subsequently been cloned through vegetative propagation, by means of shoot cuttings, so that many ‘Silver Carpet’ specimens are now flourishing here, there, and everywhere.
Tip of the Week: In addition to botanical based deterrents, there are two additional pet and critter repellents that deserve attention. One is the motion sprinkler, a device that operates like a motion light except that, instead of illuminating in response to motion, it delivers a strong jet of water, discouraging animals from hanging around. The other deterrent is electronic. With brand names such as Yard Gard and Sound Defense, the electronic devices in question emit sounds in the high-pitched, ultrasonic range, which is highly offensive to dogs. I have seen many positive reviews of these products but must confess to never having personally used any of them.