Most gardeners are familiar with a plant commonly called Swedish ivy. It is actually not an ivy at all, but a member of a plant family called Plectranthus. It is P. australis and has bright-green, round leaves with scalloped edges. It produces dainty white flowers when it gets enough direct sun and will sometimes even produce some flowers when grown indoors. It can get quite rangy unless it is regularly pinched, and even so, it is usually grown as a hanging plant.
Plectranthus is a large South African genus of the mint (Lamiaceae) family. Recently many other varieties have been discovered or developed which are more suitable for the outdoor garden because they have sturdier foliage than the original Swedish ivy and also sport attractively coloured foliage. Plectranthus are bushy plants, many with a trailing growth habit which makes them ideal candidates for hanging baskets and tall urns. They combine well with other plants and are not so vigorous as to overwhelm their neighbours. Plectranthus are not fussy about their growing conditions, and they thrive in locations with semi-shade as well as areas that receive full sun. As the amount of sun the plants receive increases, so will the amount of bloom they will produce. Because most gardeners grow these plants for their attractive foliage, they will not be concerned if the plants do not bloom. Plectranthus like a well-drained soil with lots of humus and adequate moisture. They respond well to fertilizer and are easily propagated by cuttings.
Besides the common Swedish ivy, there is a variegated form, P. coleoides, which has similarly shaped leaves but they are dark green with white edges. It is a bushy plant and produces long, trailing stems. A variegated Plectranthus with much larger leaves, P. forsteri, has enlarged six-cm-wide leaves that are very dark green with wide white margins around their edges. This Plectranthus is one of the most aromatic and when the foliage is brushed against, a pungent aroma is released. P. forsteri performs best when it gets direct sunlight and will produce attractive, coleus-like blue flowers. Another form, P. forsteri “Aureus variegatus” has green leaves with wonderful golden variegation – its leaves are smaller than those of P. forsteri and the plant is bushier.
I have grown Cuban oregano for years, but in fact this plant is not actually an oregano at all but a Plectranthus. It probably got its name because it does have a slightly oregano-like scent when the leaves are touched. It is Plectranthus ambroinicus, and is commonly grown as a pot plant. This particular Plectranthus has an upright growth habit and develops into a multi-branched, bushy plant with its small, round, felted leaves arranged in attractive rosettes at the ends of the many branches. Closely related to the Cuban oregano is P. tomentosa, which has leaves very much like those of Cuban oregano except they are spaced wider apart on the stems and the stems grow very long – it is quite a rangy, sprawling plant. Its common name, Vicks plant, comes from the fragrance that is emitted when the leaves are crushed – a Vicks-like fragrance.
I use several Plectranthus as fillers in patio containers and one of my favourites is P. argentatus, which has felted silvery leaves produced on trailing branches. The plants are quite bushy and create an excellent foil for other plants in the containers.
Another, P. ecklonii, has dark-green leaves with burgundy undersides. The blooms are similar to coleus blooms and literally cover the plants while they are in bloom.
If you like plants with uniquely coloured foliage, interesting texture and unusually aromatic foliage, you might give members of the Plectranthus family a try. They are beautiful plants both in the indoor winter garden and the outdoor summer garden.
– Albert Parsons writes from Minnedosa, Manitoba