scaredy cat / dog gone (Plectranthus neochilus)
Q 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
A 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, a powerfully pungent member of the mint family. Its foliage is succulent, leathery and fuzzy. Succulence and a leather feel ensure that water is barely lost through transpiration while fuzziness means that a soft layer of botanical fur keeps leaf temperature cool, further reducing water loss.
Locally, Dog Gone is cultivated by San Marcos Growers, a supplier of many nurseries throughout Los Angeles and the San Fernando 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 canines. It does not grow more than 6 inches tall and bears lavender-blue flowers in all four seasons.
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 have 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 to 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.
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 is known not only as a dog repellent, but for having an odor so strong that it 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 ever 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 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. How often do you need to reapply 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 reapply.
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’ subsequently has been cloned through vegetative propagation, by means of shoot cuttings, so that many ‘Silver Carpet’ specimens are now flourishing here, there and everywhere.
