I became acquainted with coleus at an early age; it grew year-round in pots in my grandmother’s kitchen. My favourite is an old standby, ‘Wizard Jade’, with creamy white centres and bright green banding on curly leaves with serrated edges. The Wizard Series of coleus (Solenostemon scutellarioides) grows about 18 inches (45 cm) tall, and its bright, beautiful leaves fill in spaces as perennials pass in and out of bloom. It grows from seed and I often see the mix with other seed-started coleus in cell packs in the spring.
The increasing diversity of coleus patterns and colours is wonderful. They’re good in large containers (several sizes and colours combined in one pot) or planted in beds and borders where they perform well in sun or shade. My best coleus one year, growing in bright shade, was ‘Wine Dipt’, a 24-inch (60-cm) beauty with a golden base suffused with deep crimson as the leaf flared to meet a brilliant lime-green edge—wow! (‘Wine Dipt’ is a variety propagated from cuttings and can’t be grown from seed.) They were eye-catching all summer, and I wanted to have them in my kitchen this winter, so I made a plan.
My grandmother always started her indoor coleus from late-summer tip cuttings, and this is the perfect time to snip a few. They’re simple to root. Take a tip cutting three to four inches (8 to 10 cm) long from a healthy, vigorous side shoot. Make the cut just below a leaf node, and remove the leaves at the node. Have ready a clean plastic pot with a drainage hole filled with moistened soilless mix from a newly opened bag, and make a one-inch (2.5-cm)-deep hole in the mix with a pencil. Dip the cut end of the stem into powdered rooting hormone powder. Insert the cutting into the planting mix, being careful not to knock off the powder. Gently firm the stem into the hole, and set the container in a plastic bag with the top left open (to make a humid environment but still allow air flow). The cutting should root within three weeks and can eventually be potted up into a larger container. Coleus likes heat, so keep the cutting in a warm, bright location.
Traditional coleus (like the Wizard Series) grown from seed thrive in part shade or dappled light. New sun-tolerant coleus hybrids propagated from cuttings (and can’t be grown from seed) are comfortable in full sun. I have also grown ‘Pineapple’ (golden yellow with a brown banded edge) and ‘Rustic Orange’ (deep pumpkin orange with a yellow edge), both in bright sun and they loved it. Other sun-tolerant coleus to look for in the spring are ‘Burgundy Sun’ (rich red-burgundy with points of bright edging), ‘Solar Flare’ (mottled green and purple with a yellow edge) and Texas-bred ‘Plum Parfait’, a heat-tolerant cultivar with ruffled purple leaves and a pink margin. All coleus need consistently moist soil (they can’t stand drought), and the sun coleus are especially moisture-reliant.
One way to divide the gardening world is between those who allow coleus plants to bloom and those who persistently snap off the flower spikes. (Although allowing annuals to flower signals the end of their life cycle, coleus is a warm-region perennial and continues to live after flowering.) I allow mine to bloom; the purple flowers are pretty and add an extra dimension of interest. Small bees love to work the flowers in early autumn. Snapping off the central flower spike frustrates the plant and causes even more flower spikes to grow on side shoots.