Cymbalaria muralis is a perennial plant that is more commonly known as Kenilworth ivy or ivy-leaved toadflax. It has long been considered a member of the Scrophulariaceae or figwort family, but more recent genetic testing shows it to actually be a member of the much larger Plantaginaceae family. Cymbalaria is native to Mediterranean Europe, but has been naturalized in many other areas including the US.
It is a trailing vine with stems that can reach over 2 feet (60cm) in length. Cymbalaria has small, scallop-shaped, light green leaves that grow with soft points on rounded edges. Plants produce small purplish to lilac-blue flowers with yellowish throats that bloom throughout the summer. These flowers are sometimes thought to resemble tiny snapdragons.
While plants can tolerate full sun, they actually prefer partial shade or at least some shade in the afternoon. They do not do well in hot and humid climates and typically grow best in cooler regions during the summer. Cymbalaria is best recommended for US Department of Agriculture (USDA) hardiness zones 6 through 9.
Often used as a ground cover or plant filler, cymbalaria also does quite well in a container. When used as a groundcover, it is generally best to keep it somewhat contained since it can be rather invasive. For best results, individuals should plant in an area with a slightly alkaline sandy or clay soil that stays slightly moist and is well-drained.
When cymbalaria plants are grown in containers, they are often prone to spider mites. Individuals should quarantine new plants away from other established plants to help keep infestations from spreading. To confirm the diagnosis of spider mites, planters should check the underside of leaves for signs of infestation. They should spray a mixture of mild dish soap and water on spider mites to help eliminate them.
Although these plants will self-seed even if the mother plant does not survive the winter, seedlings may also be grown from seeds that are germinated indoors. Seeds are typically planted about 10 weeks before the last frost of spring, and then the young seedlings are transplanted outside once the soil has warmed. When started from seed outdoors, seeds are sown on the soil’s surface after all threat of frost has passed. Cymbalaria may also be propagated by dividing the root balls once they are established.
The young outdoor plants need almost no care once they are established. They require regular watering, but care should be taken to not over-water. If fertilizing is desired, gardeners can use a water-soluble fertilizer every two weeks during the summer. To prevent spreading throughout a garden area, individuals should deadhead flowers after blooms have faded.