Coleus is an annual plant grown for its ornate foliage. It is also called painted nettle, flame nettle, and painted leaf. Coleus come in white, yellow, red, pink, purple, maroon, copper and a wide range of greens. It is native to Asia and Malaysia.
Coleus need at least six hours of sun to have the most vibrant color foliage. They can survive in partial shade but their colors are muted there. The same variety of coleus grown in the sun may look very different from one grown in partial shade. For optimal growth, and the prettiest foliage, plant your coleus where it will get morning sun and afternoon shade. Remember that in hot limates, such as in Texas or Florida, the coleus will need more shade to protect it from sunscald.
Coleus does best in most, well drained soil. Till your flowerbed down to six inches and add three inches of compost to the soil. Mix well. You can then plant your coleus after all danger of frost has passed. The outdoor temperature needs to be above 60 degrees F for the coleus to groiw properly. Temperatures in the 40s can damage your plant. Be sure you wait late enough in the season that the temperature does not fall below 60 degrees F to plant.
Space plants two to twelve inches apart, depending on the mature size of the plant. Coleus can grow to ten to eighteen inches tall, depending on the variety. Coleus make more of an impression when planted in bunches.
When you plant your coleus, pinch off the top and remove any flowers to encourage a bushier, more compact plant. Anytime the plant flowers, cut the flowers to avoid a spindly plant.
Coleus benefit from being fertilized with half strength liquid fertilizer on a regular basis. Coleus need moist but not soggy soil. The more the coleus are exposed to wind and heat, the more water it needs. It originated in a tropical area and must stay moist or it will die.
Mulch is recommended for coleus plants to help keep them moist. Do not use cedar mulch as it contains oils that are toxic to coleus. Do not allow the mulch to touch the stems of the coleus as that makes it easier for slugs to reach the plant.
Since these plants are annuals, it is a good idea to take cuttings at the end of the season and grow them indoors until spring. You can take a cutting from any non-flowering branch of the plant. Make sure the cutting is two to three inches long with at least one set of leaf nodes besides the top leaf nodes. Strip the lowest leaves off the cutting and plant it in potting soil. The lowest node of leaves (which you have removed) needs to be under the soil. That is where the roots will emerge from. You can use a rooting medium but that is not usually necessary. Keep the plants warm and moist in moderate sunlight for about two weeks to ensure rooting.