This section is from the book "The Gardener's Monthly And Horticulturist V20", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Many gardeners complain of this Coleus "running out" or turning dark; if however, they will carefully cut out all the dark shoots, and allow only the bright colored shoots to grow, the plants will be much improved. I have several large specimens planted in the open ground that are beautifully colored, and which attract considerable attention. In propagating, it is best to use only the bright colored shoots, and to use a little wood ashes in the potting soil. Cuttings struck in the Fall, keep their color better, and make finer plants than those propagated at any other time; but they should be kept warm enough to keep them constantly growing; they will then delight the grower with their beauty and richness of coloring.