Coleus: Growing and Caring for It Indoors

Botany

Coleus is a herbaceous perennial plant belonging to the Lamiaceae botanical family, alongside nettles, sage and lavender – a large family encompassing numerous aromatic and ornamental plants. Its genus name “Coleus” derives from the Greek “koleos”, meaning “sheath” or “case”, referring to how its stamens are partially fused.

In English, this plant is commonly called coleus, but it’s also known by other names such as “painted nettle”, “flame nettle” or “poor man’s croton”, due to its foliage’s resemblance to that of nettles. In the wild, coleus primarily grows in the tropical undergrowth of Southeast Asia and Africa, where it thrives in dappled light and rich, moist soil.

Although perennial in tropical climates, it’s grown as an annual outdoors in temperate regions as it cannot survive frost. Its sensitivity to low temperatures makes it an excellent conservatory plant, where it enjoys bright, temperate conditions year-round. Indoors, it’s a highly prized ornamental plant for its vibrantly coloured foliage.

Formerly classified in the Coleus genus, coleus now belongs to the Solenostemon genus, which includes over 150 species, along with numerous cultivars and hybrids. The most common varieties found in garden centres originate from Solenostemon scutellarioides (syn. Coleus blumei). These cultivars, often grouped into series by colour, are distinguished by particularly ornamental foliage ranging from soft green to deep purple, sometimes enhanced with pink, yellow or orange tones – solid, bicolour or even tricolour – offering nearly unlimited choices suitable for both outdoor annual beds and indoor cultivation.

There are many varieties of Coleus, offering vibrantly coloured foliage

Fast-growing, coleus forms beautiful bushy clumps that are both dense and ramified. Its habit is upright and slightly pyramidal, with stems that branch naturally. Depending on variety, it reaches 30 to 50 cm in height and spread within a single season. Although its lifespan indoors may be limited to a few years, it renews easily through propagation by cuttings, allowing indefinite preservation. Its main appeal lies in its foliage, far more ornamental than its flowering.

Coleus is distinguished by its ovate or triangular leaves, typically measuring between 5 and 15 cm long and 3 to 10 cm wide, though dimensions vary by cultivar. Their finely dentate edges give them a slightly crenate appearance, more or less pronounced depending on variety. Their serrated edges resemble those of nettles or mint, hence its nickname “painted nettle”. The lamina surface is often velvety, covered with fine down. Texture may be more or less quilted, with some varieties showing prominent veins that create distinctive leaf relief. Their opposite arrangement on square stems is typical of Lamiaceae. Each leaf pair grows directly opposite the previous one, creating regular, balanced symmetry. The stems, though flexible and slightly brittle, provide good support for the leaves and contribute to the plant’s bushy appearance. In some varieties, stems may also display purple or reddish hues.

The incredible chromatic diversity of its foliage is one of coleus’s main attractions. The colour palette ranges from absinthe green to acid yellow, from rust to almost black purple-red, as seen in the coleus ‘Palisandra’. Some varieties develop intense Indian pink tones, while others display more discreet cream-white hues. Depending on cultivar, foliage may be solid-coloured, bicolour or tricolour, with varied patterns like contrasting veins, marbling or differentiated edges, or with subtle gradients.

Flowering, though modest, produces small clusters of blue or purple flowers appearing in summer, but these are often removed to concentrate the plant’s energy on foliage. Fruiting remains anecdotal in ornamental cultivation as coleus is primarily grown for its leaves. However, if flowering is left, it may produce small black seeds at the cycle’s end. These seeds can be harvested and saved for home sowing, though resulting plants may show colour and pattern variations from the parent due to genetic variability in cultivated hybrids.

Beyond ornamental value, coleus has also been used in certain medicinal traditions, particularly in Asia and Africa, where extracts were used to treat various inflammatory and digestive disorders. One particular species, Coleus forskohlii (now classified in the Plectranthus genus), is known to contain forskolin, an active compound studied for its effects on metabolism and cardiovascular health. This molecule has attracted research interest for its potential role in blood vessel dilation and stimulation of certain enzymes involved in cellular regulation.

Coleus amboinicus

Main species and varieties

Coleus from the Solenostemon scutellarioides species are available in different seed series, such as the Wizard® series, and also offered as plug plants.

Our Favourite Varieties

Solenostemon Kong Mix

A cultivar that stands out with its XXL foliage! It offers a dance of green, black, and red hues.

• Flowering time July to October
• Height at maturity 45 cm

See the product sheet

Coleus Pinto Mix seeds

A sensational mix with unrestrained colours!

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Coleus Vulcan

A novelty with particularly original foliage, both in its finely dentate shape and its colour.

• Flowering time November
• Height at maturity 60 cm

See the product sheet

Coleus Rainbow Mix Seeds

One of the most popular varieties of all!

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Solenostemon Dragon Sunset & Volcano Mixed

A magnificent, slightly velvety foliage with multiple colours and fringed, curled edges.

• Flowering time July
• Height at maturity 50 cm

See the product sheet

How to grow coleus indoors?

Where to place coleus?

Coleus should be positioned in a bright environment, but without direct sunlight, which could scorch their delicate foliage. Bright indirect light or a few hours of gentle morning or late afternoon sun suit them perfectly. They prefer a stable ambient temperature between 18 and 25°C, and dislike cold draughts as well as sudden temperature fluctuations. Indoors, they thrive on a bright windowsill, a well-lit shelf, or even in a temperate conservatory where they can fully flourish.

Place the Coleus in a bright spot, ideally near a window

When to plant coleus in a pot?

Coleus can be planted or repotted year-round, but it’s best to do so in spring or early summer, when light levels are higher and the plant enters an active growth phase.

Which pot to choose?

Coleus has a shallow root system but appreciates a container with enough space to develop. A 15 to 20 cm diameter terracotta or plastic pot is usually sufficient. Ensure it has drainage holes, as coleus cannot tolerate excess water.

What substrate to use?

A mix of potting compost and well-rotted compost provides a rich substrate, promoting growth and foliage colour. Here’s an ideal blend to ensure a good balance between water retention and drainage, preventing root rot risks:

• 50 to 60% universal potting compost or houseplant compost, serving as a nutritious base and retaining the moisture needed for coleus development.
• 20 to 30% perlite, coarse sand or vermiculite, aerating the substrate and improving drainage, reducing the risk of root suffocation.
• 10 to 20% well-rotted compost, supplying essential nutrients to stimulate growth and strengthen the plant’s resilience.
• A layer of clay pebbles or gravel placed at the pot’s base to facilitate water drainage and prevent stagnation that could lead to root diseases.

How to plant coleus in a pot?

For optimal growth, it’s best to plant just one specimen per 15 cm diameter pot. If growing coleus alongside other plants in a container, leave 15 to 20 cm spacing between each young plant to avoid competition and ensure good airflow.

1. Spread a layer of gravel or clay pebbles at the pot’s base to ensure proper drainage and prevent waterlogging.
2. Fill with the substrate.
3. Position the coleus in the pot, ensuring the stem base is level with the substrate.
4. Top up with substrate and lightly firm around the roots.
5. Water moderately: an initial watering helps thoroughly moisten the substrate and encourages root establishment.
6. Place the pot in a bright spot, avoiding harsh direct sunlight.

Coleus blumei ‘Velvet’

How to sow coleus seeds?

Our coleus are available as plug plants, but we also offer a lovely collection of coleus seeds to sow in late winter or spring. Here’s our advice for successful coleus seed sowing:

1. Fill a pot with well-draining potting compost.
2. Scatter the seeds on the surface without covering them, as they need light to germinate.
3. Moisten the substrate lightly.
4. Maintain a temperature of 20–22°C and keep the substrate moist until germination, which occurs in 10–15 days.
5. Once seedlings appear, thin them out to give each young plant space and encourage growth.

Left: a small coleus seedling from sowing (the foliage colour is already visible!). Right: coleus repotted into individual pots.

How to care for potted coleus?

Coleus is an easy-to-grow indoor plant.

Watering: how and how often?

Coleus prefers slightly moist compost, without excess water.

• In spring and summer: water 2 to 3 times a week when the surface of the compost begins to dry out. It’s important not to let water stagnate in the saucer.
• In autumn and winter: reduce watering to once a week, allowing the compost to dry out a few centimetres between waterings.

Use room-temperature water, preferably non-calcareous (rainwater or filtered water). In winter, when indoor air becomes dry, lightly mist the foliage or place a tray of water with clay pebbles nearby to maintain sufficient humidity.

Fertilisation: which fertiliser and how often?

To promote vigorous growth and vibrant colours, coleus needs a regular supply of nutrients. During spring and summer, you can apply a liquid fertiliser for green plants or geraniums every two weeks to support its development. In autumn and winter, it’s best to reduce applications to once a month, or even suspend them if growth slows down.

Pruning: should you pinch or prune coleus?

Regular pruning stimulates branching and results in a more compact habit.

• Pinching young shoots: once the plant reaches 10 to 15 cm in height, pinch (i.e., cut with your fingers) the tips of the stems to encourage new branch production.
• Removing flowers: coleus flowers are insignificant and their development exhausts the plant. It’s recommended to remove them as soon as they appear to concentrate energy on the foliage.
• Removing damaged leaves: regularly remove yellowed or dried leaves to maintain an attractive appearance and prevent diseases.

Repotting

A pot-grown coleus needs repotting every 1 to 2 years, usually in spring, when the roots begin to fill the pot. On this occasion, you can choose a slightly larger container (2 to 3 cm extra in diameter) and renew the compost to provide fresh nutrients.

→ To learn more, read our advice sheet: “Indoor Coleus: Care Through the Seasons“.

What are the common problems with coleus indoors?

Although relatively hardy, coleus can be susceptible to certain pests and diseases, especially when grown indoors under inadequate conditions (excess moisture, overly dry air, poor ventilation).

Common Parasites

• Aphids: often found on young shoots, they weaken the plant by sucking the sap and can cause leaf curling. Solution: spray with black soap on affected areas (15 to 30 g of black soap diluted in one litre of water).
• Spider mites: they appear in dry conditions and cause yellowing of the foliage, with fine webs under the leaves. Solution: increase ambient humidity by regularly misting the plant and placing a tray of water with clay pebbles nearby.
• Whiteflies (aleurodes): these small flying insects lay eggs under the leaves, causing general weakening of the plant. Solution: install yellow sticky traps and treat with black soap.

Aphids, spider mites, and whiteflies

Frequent Diseases

• Root rot: caused by excess water and poor drainage, it manifests as sudden wilting of the plant and blackening of the stem base. Solution: space out watering, use well-draining soil, and ensure the pot has drainage holes.
• Powdery mildew: a fungus that forms a white powdery deposit on the leaves, favoured by excessive humidity and poor ventilation. Solution: remove affected leaves, improve airflow, and treat with sulphur or a horsetail decoction.
• Botrytis (grey mould): it often attacks plants in overly humid and cold conditions, causing rotting of leaves and stems. Solution: space out plants to improve airflow and avoid wetting the foliage when watering.

How to Prevent These Issues?

• Avoid overwatering, water moderately, and ensure good pot drainage.
• Mist the foliage regularly to prevent spider mites.
• Avoid confined spaces and space out plants to limit mould risks.
• Inspect the undersides of leaves to detect pests early.
• Remove diseased or yellowed leaves to limit disease spread.
• Use natural treatments: black soap against aphids, nettle manure to strengthen the plant, horsetail decoction to prevent fungi.

Learn more in our article: Coleus indoors: preventing and treating diseases and parasites.

How to propagate coleus?

Coleus propagates easily, mainly by propagation by cuttings, but also by sowing. Propagation by cuttings is the quickest and most reliable method to faithfully reproduce a variety, while sowing allows for new colour and shape variations.

Propagation by cuttings

Propagation by cuttings is the most common technique for multiplying coleus, as it guarantees a young plant identical to the parent. It can be done year-round indoors, but preferably in spring or summer, during active growth.

How to take coleus cuttings?

• Take a healthy stem 8 to 12 cm long, just below a node.
• Remove the lower leaves, keeping only 2 to 3 pairs of leaves at the top of the stem.
• Place the stem either in a glass of water for quick rooting (roots appear in 7 to 10 days) or directly in soil in a light, moist substrate.
• Maintain at a temperature of 20 to 25 °C, in light but without direct sunlight.
• Transplant into a permanent pot once the roots are well developed (about 2 to 3 weeks after propagation by cuttings).

Coleus propagates easily in water

Sowing

Propagation by sowing (technique described above) produces coleus with varied colours, but the characteristics of the resulting young plants may differ from the parent plant.

Our decorative ideas for incorporating a coleus indoors

Which pot to choose?

With its foliage in vibrant, contrasting hues, coleus is a plant that stands out aesthetically on its own. To avoid an overly busy visual effect, it’s preferable to choose a simple pot that will highlight its colours without creating decorative overload. Already highly graphic and colourful foliage pairs better with pots in neutral, natural tones. White and light grey bring a contemporary and elegant touch, while terracotta or matte black offer subtle contrast.

Use colour sparingly

If you’re tempted by a colourful pot, it’s better to choose a shade that complements one of the foliage tones rather than introducing an additional colour. The idea is to maintain chromatic harmony. A burgundy or plum pot will enhance a coleus with purple tones, while mustard yellow or olive green will accentuate more golden hues.

To avoid an overly busy visual effect, consider integrating your coleus into a balanced display:

• Solo: Placed on a shelf, coffee table or windowsill, it immediately catches the eye with its vibrant foliage.
• In composition: Coleus pairs perfectly with plants featuring plain green foliage, which soften its flamboyant appearance. You could combine it with ferns, pothos, calatheas or monsteras.

Coleus benefits from being paired with lush-leaved plants (here with a Monstera) for a jungle effect!