Flamboyant foliage on a versatile landscape plant
Remember when you were a kid and clumps of deep burgundy or dark green coleus grew in every shady garden corner? Well, today’s coleus is not your grandmother’s plant…or maybe it is—but those old shade lovers have been joined by an array of colorful, textured, sun-tolerant varieties. In fact, the National Garden Bureau called 2015 “Year of the Coleus.”
Because coleus—the Latin name is Solenostemon scutellarioides—is grown for its leaves, it can stay attractive throughout the growing season. There is no wait for colorful flowers or bold fruits. New cultivars of coleus appear all the time; roughly 1,500 named varieties exist, though many look the same. “One of the great things about coleus is that they can take both sun and shade, and that versatility can let you use a single plant to tie your sun and shade beds together with a common element,” says Kerry Meyer, a horticulturalist and project manager for Proven Winners, the plant brand.
In addition to unifying a garden, coleus can also be bedded out. “I also think that using coleus as a mass planting, as an in-ground planting, is underutilized. You can plant five or seven or 15 of them together in a swatch and really add a lot of impact,” she says. “Because it is foliage based, not flower based, you get that impact with no variation.” The horticulturalist also works with coleus as an “indicator plant” in mixed containers and in ground combinations. “Coleus are quick to wilt, so if I plant a coleus in a combination and then water when I see signs of wilting in the coleus, all of the plants in that combination are happy campers!”
Coleus colors run the gamut and include solid shades as well as a host of patterns and color combinations, she says. “Colors range from black to chartreuse and everything in between—burgundy, fuchsia, red, purple, orange, yellow. Patterns range from splashes of random color to solids edged with a different color and on from there.” She chooses ColorBlaze Marooned as one of her favorites, not just for its sun tolerance, excellent branching, and rich burgundy hue but also for its lateness of bloom, meaning few to no flowers to pinch off during the growing season. Meyer also admires the unique color of Keystone Kopper, a sun-tolerant version of ‘Sedona’ in a bronzy shade that almost shimmers. Both Marooned and Keystone Kopper are late bloomers, meaning there are fewer flowers to pinch during the growing season.
“You can’t tell sun or shade tolerance by looking at the plant; you need to consult the tag,” she says. “In some areas with extreme sun, you might want to provide afternoon shade, but in New England, ones labeled for sun will take full sun.”
The texture of coleus varies as much as its sun tolerance or color. Leaves range from large (several inches wide and long) to quite small (½ inch wide and long). Meyer says, “Some are smooth edged, some look like you used pinking sheers on the edges, and some are pointy along the margins. Size and habit can go from semi-trailing and only a few inches tall to four feet tall, although most fall between 10 inches and 24 inches.” The International Coleus Society divides coleus into 16 categories, based mostly on leaf shapes. These can be anything from traditional ovate leaves to short duckfoot foliage, monstrose with deformed rumpled leaves, filiform with skinny threadlike leaves, and spoon-shaped minimalist foliage.
Quenby Jaus, retail manager of Wentworth Greenhouses in Rollinsford, New Hampshire, is enthusiastic about Hort Couture’s fantastical Under the Sea collection, which grows in sun or shade. Bone Fish, for example, stands out for its bright fuchsia pink, deeply dissected leaves edged in chartreuse. “The fun colors and textures [of coleus] work well with traditional blooms to create an artistic piece,” she says, referring to Wentworth’s mixed containers.
The Kong series of plants from Ball Horticultural typifies a jumbo-leafed, bold-textured coleus. One Kong Scarlet leaf in a Stratham, New Hampshire, garden measured seven inches wide and eight inches long—an impressive measurement for a full shade coleus growing up to 18 inches high and wide. Kong Scarlet foliage has a mahogany center with serrated, lime green edges marked with deep red. Beth Simpson, owner of Rolling Green Nursery in Greenland, New Hampshire, vouches for Kong’s popularity among her customers but emphasizes that it must be grown in shade to thrive. Old-fashioned seed-grown cultivars such as ‘Rainbow’ and ‘Black Dragon’ also prefer full to partial shade; they are relatively inexpensive plants with medium-sized leaves, often available as multipack transplants.
Meyer offers specific guidelines for growing bushy, vigorous coleus for sun or shade. “When you plant, whether in containers or landscapes, add a dose of controlled release fertilizer to the soil, which should take care of the fertilizer needs for the summer,” she says. “They do need to be watered regularly and will look best if you don’t let them dry to wilt. However, if the plants do wilt, they will generally bounce back well and quickly once you do water. Once they begin to bloom, the foliage often degrades. Trim off the blooms to keep the foliage looking its best. If the plant starts to look a bit open or outgrows the space you have for it, you can trim it back at anytime—even going so far as to cutting it in half. It will branch back out and look great again in a couple of weeks. Coleus are really forgiving plants.”
If you love coleus and consider it an investment, then consider overwintering it as a houseplant. “I first got to know coleus as a houseplant at my grandma’s house, so they can certainly be overwintered indoors,” Meyer says. She suggests growing them in a bright window in order to keep them looking “green” and alive. “They will likely get a duller color and look a bit ‘ugly’ by the time spring rolls around. Don’t despair. Once the threat of frost is passed in the spring, move them outside. Wait until you see new growth and then give the plants a good trim—one third or so of the plant is a good goal.” Use water-soluble fertilizer for the next watering to get them going. “Slowly reintroduce them to sun, since they won’t be used to it after months in your home, and in a few weeks you should have the sun color back and nice, bushy plants.”
Coleus is available at nurseries and garden centers. Big box stores such as Lowe’s and Home Depot offer standard varieties of coleus and the occasional specialty plant, while local nurseries including Wentworth Greenhouses, Stratham Circle, Rolling Green, and Churchill’s Gardens frequently have more unusual cultivars for sale. You can also find interesting varieties at mail-order nurseries. Online, search for Avant Gardens (check out ‘Lemon Twist’ with filigreed burgundy edges surrounding apple green and yellow leaves, avantgardensne.com) and Rosy Dawn Gardens, coleus growing specialists offering an amazing array of plants including nine selections from the Under the Sea collection and 10 varieties from Terra Nova’s stunning coleus assortment (rosydawngardens.com).