Plectranthus – Swedish Ivy (P. australis)
The genus Plectranthus includes 250 known species of both short-shrubby and creeping plants. It is largely the creeping species that have become popular as house plants. Native to eastern Asia, Australia, & the Pacific Islands, P. australis, commonly known asSwedish ivy, is neither an ivy nor Swedish. They are particularly popular in Scandinavia where they are used for ground cover, pots, and hanging baskets, hence the name Swedish ivy. Plectranthus are especially attractive in hanging baskets, hanging down as much as 1˝ – 2 feet (45 – 60 cm).
Most of the Plectranthus have soft, almost squared stems and soft, slightly, furry leaves with shallowly scalloped edges. Characteristic of the family, all have opposite leaves and lipped or hooded flowers. Some of the plectranthus species have leaves that are aromatic when crushed, emitting a distinctive odour similar to menthol, lime, or a spicy mint. They flourish in dry air, withstand occasional dry roots, and will sometimes flower. Flowers are dainty plumes of white, pink, lavender, or blue.
Often listed in plant catalogues as tropical mints, Plectranthus are very easy to grow. They are readily propagated; grow indoors and out, in sun or shade; are unpalatable to deer, and are pest-and-disease-free.
P. australis (Swedish Ivy, Swedish Begonia, Creeping Charlie) has dark green pointed-oval, 1˝ inch (3 cm) long leaves. This Plectranthus is an erect, bushy plant that can grow 3 feet (1 m) tall.
P. australis ‘Variegata’ is a vigorous trailing and spreading plant with green and white variegated leaves. ‘Variegata’ can spread up to 18 inches (45 cm).
P. coleoides ‘Marginatus’ grows erect at first, but later trails. ‘Marginatus’ has 2 – 2˝ inch ( 5 – 6 cm) long, hairy, heart-shaped leaves with wide, creamy white margins.
P. oertendahlii (Candle plant) The most popular plectranthus, P. oertendahlii, has 1 inch (2.5 cm), almost circular, bronze-green, softly felted leaves that are strongly veined with a silvery net and purple margins. The undersides of mature leaves are purple. P. oertendahlii ‘Variegata’ is much less common than the species and has white marked leaves.
Light These plants like bright light or semi-shade. If they have inadequate light, leaf colour becomes poor and the gaps between leaves widen.
Temperature Plectranthus do well in normally warm rooms. They originate in the tropics and are frost-tender plants so if you are growing them outdoors for the summer, make sure to bring them in before temperatures drop below 50° F. (10° C).
Watering Water actively growing plants enough to keep the soil evenly moist. Do not let pots stand in water. Water sparingly when plants are resting; keep the potting mixture from drying out completely or the lower leaves will dry-up and fall off.
Propagation Stem cuttings will root very easily in spring or summer. Plant in a moist soil mixture, water moderately, and keep them in bright filtered sunlight.
Potting/re-potting Plectranthus are most attractive when young. Grow as an annual by using mature plants for propagation.
Feeding Apply standard liquid fertiliser every two weeks to plants that are actively growing.
Special Points Pinch out tips regularly to encourage branching and the development of bushy growth.