How Long Before Coleus Seedlings Show Color?

Cuttings

• Coleus plants are easily propagated from cuttings taken from a mature coleus plant. Snip one or two cuttings about 4 inches in length from the donating plant and place them in a small container of water. Cuttings will readily form roots within a few weeks and can be transplanted into a pot of soil or directly in the garden. Naturally, the new plants will duplicate the color and form of the parent plant.

Seed

• Start new coleus plants from seed indoors six to eight weeks after the danger of frost has passed for your region. Sprinkle the seed in containers of sterile potting mix and gently press them into the soil. Keep the soil moist by misting once each day. The soil must be kept at 70 degrees Fahrenheit or more until germination. Covering the seed trays lightly with clear plastic will help retain heat and moisture, but make sure there’s ample air circulation to avoid mildew. At first, the tiny sprouts will emerge as light green. In about two weeks, the leaves will start to display the colors of the cultivar or species of coleus sown.

Culture

• Certain factors will cause a decline in the vibrancy of color in coleus leaves, even in seedlings. Unless your specimen is a sun-loving variety or cultivar, full sun can have a bleaching effect on leaf color. Poor drainage and over-watering can cause “wet feet” syndrome, which may not only stunt leaf color in developing plants but may also cause root rot and kill them.

Maintenance

• As coleus seedlings grow into mature plants, they will set flowers. Coleus flowers are not particularly attractive, and flowering tends to make the plant “leggy” because it promotes increased stem growth. Flowering also causes some color loss from leaves. It’s OK to let a few flowering stems remain, but pinching most of them back will help preserve the plant’s color throughout the season. Similarly, pinching back new leaves will encourage vigorous growth.