Coleus is a gorgeous type of ornamental plant with a very complicated naming history!
In 1763, coleus was part of the Ocimum genus. Later, it was recognized as its own genus of plants. Part of the Lamiaceae family, the genus name Coleus was eventually retired and these plants were incorporated as part of the Plectranthus genus. They’ve also been classified as Solenostemon genus, which complicates things even more.
But what is coleus? Sometimes called painted nettle, they are multi-hued, stunning plants grown for their leaves rather than flowers. Excellent for either container gardening or for adoring garden beds, they offer amazing color in partial shaded areas.
Today, we’re going to narrow in on ornamental coleus plants. Other related species of coleus are used abroad as culinary herbs, medicines, or even for their edible tubers. I’ll briefly touch on a few of those too because they’re interesting, but there’s plenty to see just with Plectranthus scutellarioides.
Hundreds of ornamental coleus cultivars are available, and no two are identical, so let’s get started!
Coleus Overview
Common Name(s) Coleus, painted nettle, plus over a thousand cultivar names
Scientific Name Plectranthus scutellarioides
Family Lamiaceae
Origin Tropical areas from southeast Asia to Australia, now grown globally
Height 10-30 inches depending on variety
Light Part shade ideal, full shade also okay. Some sun tolerant cultivars.
Water Water when soil becomes dry, keep moist but not wet.
Temperature 70-100 degrees Fahrenheit
Humidity Can handle humidity
Soil Prefers extremely well draining soil
Fertilizer Balanced liquid or slow release granular, 10-10-10 ideal
Propagation By seed or cuttings
Pests Susceptible to mealybugs, aphids, spider mites, whiteflies, and slugs. Also susceptible to fungal root and stem rot and downy mildew.
Types Of Coleus
Ornamental Coleus Varieties (aka Plectranthus scutellarioides, Solenostemon scutellarioides, or Coleus blumei)
There’s so many ornamental varieties of this fascinating plant that I can’t show them all. However, these are some of the most popular cultivars available right now.
Plectranthus scutellarioides, ‘Wizard'
There are multiple coleus varieties that fall under the designation of “Wizard”. A coleus Wizard mix can be an eye-dazzling display of a very wide variety of colors. Some of the specific varieties that fall under this designation are Wizard Jade, Wizard Rose, Wizard Velvet Red, Wizard Golden, Wizard Coral, Wizard Coral Sunrise, Wizard Mosaic, Wizard Pastel, Wizard Pineapple, Wizard Scarlet, and Wizard Sunset.
Each of these has a vastly-different color combination. Reds, yellows, oranges, almost-white, green, pink, purples, and near-blacks are available in the Wizard cultivar selection.
Plectranthus scutellarioides, ‘Volcano’, ‘Red Velvet’, ‘Festive Dance’
The Volcano cultivar, along with its relatives Red Velvet and Festive Dance, are all part of the “Superfine Rainbow” series of cultivars. These varieties have leaves edged in yellow to pale green, with a deeper red hue covering the remainder of the leaf. Festive Dance goes a step further by having spining in a deep magenta on a red-orange background with pale green lacy edging.
All three of these varieties are known for their lacy edge coloration, and are quite popular in the garden as a result.
Plectranthus scutellarioides, ‘Kong’
The “Kong” series of cultivars are plants with bicolored or tricolored leaves. Typically edged in green, the leaves graduate into shades of red, maroon, or pink towards the center. Available in Kong Scarlet, Kong Lime Sprite, Kong Rose, or Kong Red variations, as well as a mix referred to as the Kong Empire Mix. Kong Rose is an especially popular variety.
Plectranthus scutellarioides, ‘Florida Sun Rose’
These unusually-colored types of coleus feature pale to rosy pink edges with a deep purple center that is almost black. Often, there will be green, yellow, or red highlight colors as well. Florida Sun Rose is typically an upright grower but can develop a trailing habit, which makes them quite good as container plants.
Plectranthus scutellarioides, ‘Inky Fingers’, ‘Inky Toes’
Inky Fingers, and its relative Inky Toes, both feature a green outer edge with a magenta interior leaf. Inky Fingers has more of a spreading pattern that resembles a hand. By comparison, Inky Toes has more of a blot-like pattern with a few short extensions of color from it. These are popular when used as a bed filler around taller-reaching flower varieties. They also make excellent container plants, as their duckfoot-shaped leaves are quite enjoyable on their own.
Plectranthus scutellarioides, ‘Peter Wonder’, ‘Peter’s Wonder’, ‘Pink Ruffles’
With bright pinks, vibrant greens, and creamy off-white hues, Peter’s Wonder offers a cacophony of color in a garden setting or hanging basket. These leaves are frilly, with brilliant pink to magenta veining. A rich yellowed ivory backdrop houses even patches of green segmentation. One of the more striking varieties, these have been popular for a long time.
Plectranthus scutellarioides, ‘Black Dragon’
The leaves of the Black Dragon variety of coleus are more intense than many flower petals! These richly-shaded magenta to black leaves offer a depth of color. A great backdrop or surround for white or creamy-colored flowering plants, Black Dragon cultivar is prized by gardeners worldwide.
Plectranthus scutellarioides, ‘Wasabi’
Lest you think all varieties are intense in color, here’s one which is a bit more subdued. Wasabi is a beautiful shade of bright green. But its appeal comes in its elegantly-shaped leaves. Surprisingly popular in combination with other varieties, the coleus Wasabi is definitely one to have in the garden.
Plectranthus scutellarioides, ‘Campfire’
If you’re looking for something to bring autumnal shades into your summer garden, this plant is an excellent choice. Campfire coleus is vivid orange in hue, occasionally with deeper rust veining or edging.
Plectranthus scutellarioides, ‘Henna’
Henna coleus pairs up extremely well with Campfire to produce the effect of fallen autumn leaves. Its feathered and slightly curled leaf shape, mixed with its yellow and rust coloration, mimics autumn’s tones perfectly.
Plectranthus scutellarioides, ‘Watermelon'
For entertaining summer-filled color, you can simulate the effect of thousands of watermelon slices in your yard! Watermelon coleus has green-edged leaves with rich red centers. It’s as visually delicious as its sweet namesake.
Caring For Coleus
Coleus care is super-easy, and gardeners far and wide love it. With just a few simple hints, anyone can grow this ornamental! Read on to find out just how easy it is.
Light
Although it loves warm climates, coleus light requirements are minimal. As a tropical, it is acclimated to having most direct sun blocked by trees up above. The scorching rays of the sun can bleach those gorgeous leaf colors, so try to provide at least some shade for best appearance. For the best color, provide early morning sun and afternoon shade.
Some varieties like the Wizard series are more sun-tolerant. If you have minimal shade available, pick those varieties.
The ideal temperature for these plants is between 70-100 degrees. Obviously, heat isn’t an issue! However, cold can be. If the temperature begins dipping below 50 degrees, use a cold frame to keep them warm. Alternately, bring them indoors and provide indirect light for them in a warmer location.
Water
When you first plant your plant, water it until the soil is saturated. Afterward, avoid heavy watering as it can cause root rot and leaf drop. Water only when the soil becomes dry, and keep it at an even moisture. You do not want muddy soil, just lightly moist!
Soil
Plectranthus scutellarioides prefers well-draining soil. Don’t use soils that contain a lot of vermiculite or polymer moisture absorbers. A blend which has lots of perlite is preferable, as it keeps the soil aerated while improving drainage.
It’s also important to mulch your soil’s surface with a gravel mulch. This keeps moisture in the soil and reduces watering frequency. Having mulch beneath the plants will also help prevent disease spread.
Fertilizer
If your plants are in containers, feed once a month with a balanced, water-soluble fertilizer. If they are in a garden bed, a slow-release granular fertilizer is fine too. 10-10-10 fertilizer is great for these plants. If that’s not available, opt for one which is higher in nitrogen than everything else, as that will spur leaf and plant growth.
Propagation
Coleus can be propagated by seed or by cuttings.
By seed, it is easiest to use a seedling tray filled with potting soil and broadcast seed evenly across the surface. Once the seed is spread, put a thin layer of potting soil overtop. Place a plastic cover over the seedling tray and place in bright, indirect lighting in a warm spot.
You should begin to see seedlings within two weeks. When they appear, remove the plastic cover. Keep the soil moist but not wet. It’s safer for your seedlings if they are watered from the bottom of the tray rather than overhead.
By cuttings, use a sharp and clean pair of scissors and remove 4-6″ segments from your plants. Make the cut right beneath a leaf node along the stem. Dip the cut end into rooting hormone.
Using a pencil, make a hole in your prepared potting mix and gently place the cutting into the hole. Gently press the soil back around the stem. Place your planted cutting into a plastic bag, being careful to keep the plastic from touching the cutting.
Keep the soil moist, but not wet, and keep it in a warm location with indirect bright lighting. Your plant should take root within a couple weeks. You will know rooting has occurred if new growth begins to form. At that point, you can remove the plastic bag.
Repotting
When repotting, do not plant the coleus any lower in the pot than it was originally planted. Prepare your larger pot with a good quality potting soil, then remove the coleus from its other pot. Gently separate the root mass with your hands, then place it in the new pot. Be careful not to break its large taproot!
Using your hands, scoop soil around the plant’s base to fill in any gaps, and lightly press down to secure it in place. Do not tightly pack the soil, as nature will pack it down for you.
Pruning
Most people love flowering plants. In this case, the leaves are much better than the flowers! When you see a coleus flower, pinch it off before it can bloom. As these are typically annuals, they can die off after flowering. Pinching the blooms off redirects the plant’s energy to leaf and plant growth instead of seed formation.
Like most mint relatives, these can rapidly become spindly. To encourage a more bushy formation, cut or pinch off leggy stems just above a leaf node. It’s best if you choose a node that has a visible bud forming, as it will encourage the plant to fork at that location.
Problems
Growing Problems
Since coleus is shade-loving, plants which are grown in full sun conditions can experience scalding of the leaves. This shows as leaves with faded color, burned or crisp leaf edges, and occasionally translucent patches on the leaf’s surface that can turn into holes. These symptoms can be more prevalent or occur more often if the plant is underwatered or overwatered.
To avoid leaf scalding, ensure that your plants have at least partial shade conditions. Afternoon shade tends to be better than morning shade, as the sun is more intense in the afternoon. If you must plant a coleus in a full sun location, pick a variety which is sun-tolerant. There are many varieties bred for sun tolerance now, so there’s a wide selection to choose from.
Pests
Only a few varieties of pests tend to be an issue with coleus, and even then, the plant tends to bounce back from them quickly.
Mealybugs can leave a whitish residue along stem joints and will suck the plant’s sap out. Aphids are also a sap-sucker, and can quickly cause a plant to wither if they’re present in large quantities. Whiteflies, too, will drink your plant’s sap, and you can easily see when they’re becoming a problem in the garden or greenhouse. And then there are spider mites, which will feast on both the plant’s leaves and the sap, leaving a fine web-like material behind.
All four of these pests can be dealt with using an insecticidal soap such as Safer brand insect killing soap. To prevent these insects from ever infesting your plants, you can use regular applications of neem oil as a deterrent. Also, beneficial insects such as ladybugs or lacewings will happily feast on all four of those pests, keeping them at bay.
There is one other pest which will nibble your plants into oblivion: the common garden slug. They creep in at night and feed, and may take up residence beneath your plants during the daytime. A bait such as Garden Safe Snail & Slug Bait will distract the slugs from your plants. As they eat the bait, they become poisoned and will die off.
Diseases
Overwatering your plants can cause fungal issues such as stem rot and root rot. A wooden mulch can also be the culprit, as it soaks up too much moisture and can create stem rot where it touches the plant. Avoid overwatering to avoid the rot, and use gravel mulch beneath your plants as it dries out quicker.
If stem or root rot becomes apparent on your plants, prune off all signs of the rot, and transplant it to a new sterile potting soil.
To do this, you should carefully remove your plant from its pot or bed. Using a bucket of clean water, swish the roots around to dislodge any of the fungally-infected soil and wash it away. Then, examine the roots. Trim any which have become brown or mushy. If the central taproot has become rotten, the plant should be destroyed. Also trim off any stems which have succumbed to stem rot.
Repot your plant in sterile potting soil. Once it is back in soil, cleanse your scissors or other cutting tools used with a mixture of one part bleach to three parts water. This will kill off any remaining fungal spores that may be on the tools. Do not replant in infected soil. Avoid overwatering your plant to prevent further rot issues.
Downy mildew may also become a problem. This is also a fungal issue caused by spores, and while it can happen outdoors, it’s far more prevalent in greenhouses. However, you can treat this with neem oil. Spray the oil thoroughly throughout the plant, being sure to coat both the tops and bottoms of leaves. You may need to regularly treat your plant every few days until signs of the mildew disappear. Prune off any leaves which were damaged by mildew after treatment is done.
Frequently Asked Questions
Q: Is coleus monocot or dicot?
A: It is an herbaceous dicot. It has a longer, thicker taproot surrounded by smaller roots, and forms net-like veining in its leaves. It also has multiple flowers instead of single flowers on a stem.
Q: Can coleus be perennial?
A: While most people grow it as an annual, yes, it can be perennial. However, it would be considered a tender perennial, as it is not at all frost-resistant. If you are in an area which never gets frost, you may be able to overwinter it outdoors in a cold frame or a greenhouse. However, anyone in a location that gets frosts or freezes should bring it indoors or place it in a heated greenhouse to protect it. If the temperature is below 50 degrees Fahrenheit, it may begin to die back.
Intense colored leaves and intricate patterns mean that coleus can really bring a visual highlight to your container garden or shady garden space. Have I inspired you to try this low-maintenance tropical plant yet? I know I’m eyeing some of the Wizard cultivar for spring planting next year! What’s your favorite of the hundreds of coleus varieties? Tell me in the comments!