What Are the Best Tips for Growing Coleus?

Growing coleus well is best done by trying to match the plant as much as possible to its native conditions. Since coleus is a tropical plant found throughout Asia, Africa, and the East Indies, it prefers warm temperatures and a fair amount of sunlight. Coleus are perennial foliage plants that aren't meant to flower or go to seed, so, unlike flowering plants, they require less fertilizer and can also thrive in partially-shaded conditions. As a tropical plant, they prefer moist soil, so growing coleus plants must be watered frequently as well. Caring for coleus plants, if they are indoor container plants or placed outside where the growing season is long, should also include cutting stems back so that the plant becomes bushy instead of tall and thin.

Though growing coleus does not require heavy fertilization, it is recommended that it be fed fertilizer every two weeks if it is a container plant using a balanced concentration of nutrients, and fed about half as much if it is planted outdoors. Due to the plant's tropical nature, it cannot stand cold temperatures and is only hardy to zone 10, which is close to the equator. This means that temperatures below 50° Fahrenheit (10° Celsius) will damage the plant. Since it is a perennial, however, it can be overwintered if kept in the sun indoors. House plants like coleus tend to root very easily, so growing coleus can be relatively simple if tip cuttings are made to propagate the plant in new pots, should the parent plant fail to survive.

If a coleus begins to flower, it is recommended that the flowers be cut off, as they will take energy from the plant's growth and detract from its appearance. The colors of the leaves are most vivid when growing coleus if they are not kept in bright, direct sunlight, and the ideal temperature for them to flourish is 60° Fahrenheit (16° Celsius). When the coleus plant starts to have dead leaves, the opposite of too much sunlight is the problem, and either the light level is insufficient or the area in which the plant is being kept is too cold for it.

The official origin of coleus is Indonesia, with the plant arriving in Europe in the middle of the 1800s and the UK by the 1860s. Two species serve as the ancestors of all modern coleus in the west — C. verschaftelti and C. blumei — and 150 varieties or more have since been bred from these two strains as of 2011. Around 60 varieties are sold in the US, and most of them are descended from C. blumei. Coleus has also been crossed with many other plants to produce hundreds of new hybrid ornamental strains.