Coleus is a herbaceous ornamental plant with brightly coloured leaves

Other names for coleus

Coleus, also called wucai su, laolai shao, wuse cao and jin zisu, is a perennial herbaceous foliage-type ornamental flower of the genus Coleus in the mint family Lamiaceae.

Morphological characteristics of coleus

Coleus is a perennial herbaceous plant; old plants can grow into a subshrub form, but the plant shape is unattractive and its ornamental value is low, so it is mostly grown as an annual or biennial. Plant height is 50~8Ocm, and cultivated seedlings are mostly kept below 3Ocm. The whole plant is hairy, the stem is four-angled and woody at the base, the leaves are simple and opposite, ovate, with a long acuminate tip and blunt teeth along the margin; leaves can grow to l5cm, the leaf surface is green with bright markings in pale yellow, peach red, vermilion, purple and so on. The terminal raceme bears small flowers that are light blue or light purple. The nutlets are smooth and glossy.

Growth habits of coleus

Coleus is a warmth-loving plant with strong adaptability; the winter temperature should not be lower than 10°C, and in summer it needs a little shading during high temperatures. It likes ample sunlight, and sufficient light makes the leaf colours vivid; it likes moisture, so in summer it must be watered thoroughly, otherwise wilting easily occurs. Also spray water on the leaves regularly to maintain a certain air humidity; apply more phosphorus fertiliser to keep the leaves vivid. Avoid applying excessive nitrogen, otherwise the leaves become dull; it requires loose, fertile soil, and ordinary garden soil is generally sufficient.

Coleus flower language and legend

The flower language of coleus is a hopeless romance, expressing innocence and despair. It is said that coleus has seven leaves, and the colour of each leaf is different; in the dark it gives off seven-coloured light, like a colourful luminous pearl. It is said that coleus is spiritual: if a person with a pure heart owns it, it will shine and bring you happiness; otherwise, it will gradually wither and lose its brilliance.

Variety classification of coleus

According to the propagation method, coleus can be divided into two types.

Seed-propagated types

1, Large-leaf type, with large ovate leaves, tall plants, few branches and an uneven leaf surface.

2, Colourful-leaf type, with small, long elliptical leaves, pointed tips, a smooth leaf surface, and leaf colours including red, orange-red, yellow-green and green with white patches.

3, Crinkled-edge type, with leaf margins split and wavy-crinkled; the cracks and ripples vary greatly, and the leaf colours are also very diverse.

4, Willow-leaf type, with slender, willow-like leaves, and leaf margins bearing irregular incisions and serrations.

5, Yellow-green leaf type, with small, yellow-green leaves, resistant to sunscald, and plants that are short and much branched.

Vegetatively propagated types

1, Five-colour coleus, with markings on the leaves in pale yellow, peach red, vermilion, dark red and other colours.

2, Small-patterned coleus, native to the Philippines and Sri Lanka. Plant height 15~20 cm, perennial herb, with a prostrate stem. Leaves opposite, rhombic, 2~3 cm long, dark brown on the surface, green at the margins and pale on the underside. Flowers blue-green, in panicles 10~12 cm long.

3, Clustered coleus, a subshrub, plant height 80~100 cm, leaves bright green, heart-shaped ovate. Margins with coarse serrations. Flowers bright blue, in verticillasters, with 3~10 flowers arranged in spikes. Flowering period 11~12 months, grown in pots in winter for viewing the flowers.

Coleus picture appreciation