Plectranthus is a large genus of plants native to areas in the Southern Hemisphere containing approximately 350 species. Plants in the Plectranthus genus are closely related to mint as they are part of the same family—the Lamiaceae family. The Plectranthus genus is characterized by both annual and perennial plants, many of which are used for food, ornamental, and medical purposes. Many Plectranthus species share common characteristics including aromatic and colorful foliage, and leaves that tend to be wavy, toothed or scalloped on the edges. The Plectranthus genus is characterized by both shrubs and ground cover plants.
Plants in the Plectranthus genus can commonly be found growing outdoors as ornamental plants in containers or gardens, as well as indoors as houseplants depending on the species. Plectranthus species are usually low-maintenance, and fast-growing, which makes them attractive options for even the most inexperienced gardener. Some of the most well-known Plectranthus species include the Plectranthus scutellarioides, commonly known as coleus, and the Plectranthus ‘Mona Lavender,’ which has become a popular houseplant.
|Plant Type||Annual, perennial|
|Mature Size||150mm - 2m tall|
|Sun Exposure||Full sun or partial shade|
|Bloom Time||Spring, winter, fall|
|Flower Color||Purple, pink, white, and blue|
|Hardiness Zones||8 to 11|
|Native Area||Africa, Madagascar, India|
How to Grow Plectranthus
Generally, plants in the Plectranthus species are easy to grow and do not require too much attention or special treatment. They do best in locations that provide partial shade although some species can handle growing in full sun if necessary. They are shallow-rooted plants that appreciate adequate water but can tolerate short periods of drought as they store water in their stems. They are easily propagated, and only require pruning for cosmetic reasons. Plectranthus species are not frost-tolerant, but the perennial species will come back after each winter in locations that receive cold winters.
Plectranthus plants can flower multiple times a year and tend to flower at the end of the season, during the shortest days of the year in winter-hardy zones, or in cool summer climates. Depending on the species, flowers can be purple, pink, white, or blue.
The exact amount of light needed to grow Plectranthus depends on the species. However, as a general rule of thumb, most Plectranthus species appreciate bright, indirect light. Very few can tolerate direct sun and may suffer from leaf burn if exposed to direct sun for too long. When growing Plectranthus outdoors, choose a spot that receives sun for only part of the day, or a spot that is in the shade completely like beneath a tree. When grown indoors, a location that receives direct light for most of the day is ideal.
One of the most important parts of growing Plectranthus is ensuring they are planted in a well-draining potting medium. Plectranthus do not tolerate ‘wet feet’ - meaning their roots cannot sit in wet or soggy soil for prolonged periods of time. Standard potting soil mixed with perlite or sand should provide adequate drainage.
Plectranthus require regular watering in order to thrive. Water once the top inch or two of soil has dried out, and be careful not to overwater. The soil should stay moist, but not wet. It is important to note that water needs may vary from species to species.
Temperature and Humidity
While Plectranthus is not a frost-tolerant genus, plants in this genus do well in colder temperatures and even flower during the shorter days of the year. Since the Plectranthus genus is comprised of both annual and perennial species, the exact temperature requirements vary from species to species. However, as a rule of thumb Plectranthus does not tolerate temperature extremes well. In extremely hot climates, Plectranthus may struggle and require extra care (watering and shade) to survive. In cold climates or snowy winters, Plectranthus species will not survive but may come back in the warmer spring months depending on the species. Some gardeners choose to move their Plectranthus plants indoors for the cold winters, which allows them to survive throughout the year.
Plectranthus appreciate monthly fertilization during their active growing period, from the spring to the fall. A standard 10-20-10 plant fertilizer should be sufficient for most varieties.
Plectranthus species are easily propagated through both division and cuttings. The best time to propagate is during the spring or early summer. To propagate by division, simply divide the plant into several new plants by separating the stems and roots. To propagate by cuttings, take cuttings of the stems (be sure to get pieces with leaves attached) and place in water until roots begin to grow. Transplant the rooted cuttings to soil to complete the propagation.
Varieties of Plectranthus
There are over 350 species in the Plectranthus genus. Some of the more popular varieties include:
- Plectranthus scutellarioides, also known as Coleus (many sub-varietals)
- Plectranthus amboinicus, or Mexican mint
- Plectranthus ‘Mona Lavender’
- Plectranthus parviflorus ‘Limplepl,’ or Blue Yonder
- Plectranthus forsteri, or Green on Green
- Plectranthus verticillatus, or Swedish Ivy
- Plectranthus tomentosa, or Vick’s plant
Species in the Plectranthus genus can be pruned regularly to help them maintain an attractive shape. Shrubby varieties look best when they are cut back and shaped into more dense bushes. Ground cover varieties grow quickly and may be pruned regularly to prevent them from becoming overgrown.