How to trim coleus plants
You need to trim coleus plants to make the plants bushier and preferably as far down as possible. You should cut above a pair of leaves and there the plant will stop growing upwards and instead it will branch out at the pair of leaves into two new branches. The more you cut, the more branches form and the bushier the plant becomes!
If your plant begins to flower, you can try to interrupt the flowering by cutting off the flower buds. Cut two pairs of leaves below the flower buds. The plant's fine colors are retained longer if the flowering is interrupted.