Coleus (Solenostemon sculellaniodes ) drifts in and out of popularity with gardeners: We’ve seen it shift from the Victorian era, to the 70s and 80s plant collectors, and, now, propelled into the twenty-first century with an explosion of hybrids able to live in a range of light exposure.
Chris Baker, longtime coleus breeder at Baker’s Acres Greenhouse in Ohio, admits that usually he gets asked which coleus does best in sun – and answers that most do.
Gardeners are returning to coleus for their shade gardens: A proven idea to replace the bedding plant Impatiens wallierana that has been less reliable in recent years. We plant coleus for color to brighten beds under tree canopies and in north-facing locations. We have resurrected old stalwarts and plant breeders are growing new varieties to brighten those shady spots.
Annual Coleus in Shady Planting Beds
We grow coleus or its colorful annual foliage; it brightens most dark locations outside and indoors. Painting with the foliage of coleus in a shady planting bed will result in a rainbow of colorations.
In speaking with Decoded Plants, Baker said, “All coleus do well in shade. Some just look different. Even an unshaded greenhouse is darker than full outdoors sun. The direct sun will change the color of some coleus, bringing out the darker reds and browns. Usually what you see is what you get when putting a coleus in the shade.”
Characteristic Coloring and Plant Habits of Coleus
Among coleus varieties, there are wildly varying plant habits, leaf forms, and colors; it may take a little trial and error to achieve the look you want. The colors in coleus leaves perform differently in shade over the sunny locations you may have been using.
A gardener’s general rule of thumb: Dark leaves of coleus in sunnier locations and lighter colored leaves of coleus in more shade or less sun. Solenostemon ‘Vino’ is a burgundy coleus with a slim lime green edging: The sunnier its location the darker the burgundy will evolve, blackening its leaves in full sun.
Peter’s Wonder is a classic for testing light: Its cream colors will turn reddish and the green areas brown with increasingly sunnier exposure. It is a good choice for a spot with early morning sun and afternoon shade.
The plant habits and leaf-forms of coleus gives a gardener many design choices. The Kong series is popular for its huge leaves. As a large-leaved coleus grows it creates a “scaffolding” look that will make a dramatic single plant in a small garden. The 2014 Kong, Jr. variety likes part sun or shade that grows in classic Kong tricolor colors, but in a smaller package of plant that keeps its bigger cousin’s layered appearance.
Small-leaved coleus such as Inky Fingers, called a fingered-leaf form, or Baker’s elongated Kiwi Herman can be shaped into a carpet effect when planted en mass.
Burgundy Wedding Train works in shade and part shade and resembles the duckfoot-leaf form, but whose leaves are less dissected than, for example, India Frills.
New gardeners can narrow the field of coleus by looking for hybrids and varieties which are labeled for part shade or shade. The list of Solenostemon sculellaniodes is long but distinguished: Seed strains Fairway and Main Street, slow bloomer Night Skies with a starry pattern, and Alabama Sunset in pink, red, orange and reddish hues are just a few.
And like coleus enthusiasts, gardeners may sneak in a few choices for their shady gardens just for the play-on-names: Gnash Rambler, Brownie Points, and Holy Guacamole, for instance.
Seed Strain Coleus Varieties
As for mass plantings, seed strain coleus that has robust size will make an impressive display. The miniature varieties like Thumbelina or Under the Sea are better for very small gardens; in a raised bed, or surrounding a patio.
Baker advises, “Also avoid seed varieties (Kongs, Wizards) because they bloom so soon, which distracts from the foliage.” The earlier a coleus plant starts blooming in a growing season, the more time you will need built into deadheading and your plant maintenance schedule.
Gardeners who love to start their plants from seed, though, have plenty of varieties to choose from: Black Dragon, Wizard, Superfine, Rainbow, Giant Exhibition, Chocolate, Mighty Mosaic, and Kong series. Plan your garden early and start the seed strains 8 – 12 weeks before your last frost date.
The new seed strain variety Mighty Mosaic is very late flowering in shade, or sun where there is high humidity. It has colorful foliage and an upright form in a 10” – 24” plant size.
Growing Annual Coleus Plants for En Masse Plantings
Coleus is a low maintenance annual plant and if you have one or three in a garden the plant care is quick. Planting coleus en masse (planting many plants in one bed for a continuous look) is going to naturally multiply the maintenance required.
Plant breeders are searching for new hybrid coleus that holds off flowering until later in the season. Though, gardeners are still encouraged to pinch off the flower stems (called deadheading) to help the plants grow well whenever they appear.
A coleus’ best growing conditions are still part shade or dappled light, or a location with morning sun and then afternoon shade. Coleus needs average moisture and should not dry out, especially in sunny gardens. Coleus grow best when daytime temperatures are below 95°F and nighttime temperatures are above 50° F. The leaves should not burn, but do avoid cold damp soil.
Impatiens Downy Mildew Impacts What Shade Gardener Grow
A collection of coleus plants is a source gardeners can look to for renewing their shady landscapes. Since the discovery of the impatiens downy mildew in our backyards, gardeners have searched for new ideas to fill those bare spots of shady ground.
The devastation brought on by the pathogen, Plasmopara obducens, has pushed gardeners to finding alternatives for adding color in the darker locations of planting beds around the yard.
Coleus Plants Remain a Favorite Annual for Shade Gardens
Solenostemon sculellaniodes is the current botanical name for the favorite annual of plant collectors and shade gardeners: coleus.
Many greenhouses schooled in botanical nomenclature, still keep to the simple moniker of “Coleus” for signage.
Coleus was once called Coleus blumei, but is, since 2006, Solenostemon sculellaniodes.
Whatever you call it, coleus is a simple annual plant and easy to grow. Its plant structure is a good choice for new gardeners or children to learn, and its plant care easy for busy gardeners to maintain.