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Cape lilac Plectranthus ecklonii (Photo by Joshua Siskin)
Cape lilac Plectranthus ecklonii (Photo by Joshua Siskin)
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In a planter next to the entrance to his house in Northridge, master gardener Rex Kiddoo had the wisdom to plant Plectranthus ecklonii, whose happiness in that location is evidenced by its plethora of blooms. 

This species, which can serve as a ground cover or a low shrub as long as it is regularly trimmed back, will grow six feet tall when left to its own devices. One of the common names given to this beauty is cape lilac due to the color of its flowers and its Cape of South Africa habitat, where it grows as an understory plant in a subtropical, coastal forest. Kiddoo’s plant faces north so it does not see direct sun and gets about the same amount of light as his azaleas. 

Cape lilac is one of those plants that grows effortlessly in any soil type and is easily propagated; detach a six-inch cutting and, after removal of the bottom leaves, insert it directly into the soil at this time of year or in early spring. It can also be propagated from stem cuttings placed in potting soil in a container. Finally, all Plectranthus species, in the manner of their closely related Coleus cousins, will sprout roots along stems submerged in water before your very eyes. Just be aware that rooting happens fastest during the growing season and will take considerably longer as daylight hours become scarcer with the approach of winter.

In truth, there are many horticulturally desirable Plectranthus species, although they seem to be something of a mystery. We seldom see them in the nursery, but there are 85 Plectranthus species altogether, and another 600 hybrids and varieties. All are perennial. Among my favorites is Mona Lavender, which thrives in shady locations. In the manner of cape lilac, it blooms most heavily in the fall. It grows two feet tall and has leaves that are sea green on top and purple underneath. Since it could die in a hard freeze, you would be wise to propagate it and grow some of its clonal offspring as indoor plants. Bear in mind, however, that when plants that flower in the shade outdoors are situated indoors, they will require lots more light to bloom, probably as much as you can provide. If your indoor environment is less than bright, you will need to utilize artificial light in order to get flowers, regardless of how little light was needed for blooming outdoors.

The malodorous Plectranthus neochilus has the common names of dog gone and scaredy cat due to its capacity to discourage trespassing on the part of canine and feline creatures. In its native South Africa, it is even promoted for its ability to deter snakes. Due to its leaf texture, it is also sometimes labeled Fuzzy Wuzzy.  In any case, this is a ground cover that is nearly always in bloom. On the northern coast of Israel opposite the Mediterranean Sea, it is planted in sandy soil adjacent to the beach. Once established, as long as there is a little winter rain, it does not need any summer irrigation. 

The Plectranthus genus of plants belongs to the mint family, and some are pleasantly aromatic, including mentholato (Plectranthus cylindricus) and Cuban oregano (Plectranthus oregano), also known as Mexican mint, whose leaves – both fresh and dry – may be used in cooking. 

No discussion of this genus would be complete without mentioning Swedish ivy (Plectranthus verticillatus). Its common name is a misnomer since it is not Swedish (it was popularized there but is indigenous to South Africa) and does not produce roots that cling and allow it to climb like ivy, although its bright green, one-inch leaves do trail along the ground. Swedish ivy once adorned the mantle above the fireplace in the Oval Office, where it was designated as “the most photographeed plant in the world” since it – or plants propagated from its cuttings – grew there from 1961 into the Obama presidency, only to finally be replaced by grape ivy (Cissus rhombifolia), which remains there until today. Grape ivy, incidentally, although also without clinging roots, is actually related to the grape we cultivate for eating and for wine and, like the grape plant, is possessed of tendrils that allow it to wrap its way around and up trees and trellises.

Incidentally, Rex Kiddoo’s cape lilac may be ordered from Annie’s Annuals (anniesannuala.com), along with three other members of the Plectranthus genus, while San Marcos Growers (smgrowers.com) has a dozen species in production. Most notable among the San Marcos selections is silver Plectranthus (Plectranthus argentatus), which grows up to six feet tall. In addition to foot-long wands of pinkish-white flowers at this time of year, stems of its silvery leaves will last for two weeks when placed in vase arrangements.

California native of the week: Western meadow rue (Thalictrum orientale) has daintily laced foliage as decorous as any you will ever see. Plants are dioecious, meaning they are either male or female. Male flowers are produced in huge numbers. They are alluring and arresting to behold with long reddish stamens tipped in purple. Female flowers are collections of little white clubs. This is a plant that self-sows and has the potential to become weedy, although it seems like it would be a nice weed to have around. It is called rue because its foliage resembles that of the herb known simply as rue (Ruta graveolens) in two distinctive ways. First, the blue-gray foliage of rue, like that of Western meadow rue, is delicate, blue-gray, and highly aesthetic; second, both plants emit a strong, unpleasant smell. Ordinary rue, native to the Balkan peninsula, was used in the Middle Ages as a strewing herb that was spread on the floor of churches since it was thought that its repellent odor would keep away the devil. 

For more information about area plants and gardens, go to Joshua Siskin’s website, thesmartergardener.com. Send questions and photos to Joshua@perfectplants.com.