It produces tiny blue to white flowers; however, they are unimpressive and are frequently cut off to save the plant's energy. The shape, style, and color of the leaves can all be quite different. New introductions with even more odd colors and patterns are introduced regularly by breeders.
Coleus, when planted outside in early spring, grows to full size in a single season. In a landscape or garden bed, large expanses of various coleus plantings that take on a quilt-like appearance can look delectable. Window boxes, outdoor container plants, and hanging baskets benefit from its brightly colored foliage. Coleus is poisonous to animals.
Coleus is a delicate tropical plant that grows near the equator. Coleus can be grown as garden perennials in warmer climates, where they can develop to resemble tiny shrubs with thick woody stems. Though it thrives in the heat, it can be grown annually in almost any garden and is commonly used as a bedding plant or in containers.
On the other hand, Coleus plants are not frost-tolerant, so don't rush into planting them. Before putting them in the garden, wait until temperatures are consistently over 60 degrees Fahrenheit. They want rich, loose soil, so enriching it with compost or peat moss before planting is recommended unless you have quality soil.
Coleus is a traditional part-shade to full-shade plant; however, the amount of light it receives varies by variety. The old-fashioned seed-grown coleus thrives to full shade, but the newer cultivars provide their greatest color when grown in full sun.
However, it is also dependent on your geographical location. If you reside in a hot, dry climate, all sorts will require some shade, especially in the afternoon. Shade coleus will need more sun exposure in chilly climates with shorter seasons to help them warm up.
Throughout the warmer (brighter) months, plants grown in containers usually get plenty of light from indirect sunshine, but they may need to be exposed to filtered sunlight during the winter. They don't require much, but they require direct light.
Coleus prefers moist, rich, loose soil that is continually moist. Compost or another organic material should be added to the ground before planting. Any good-quality peat-based potting mix will suffice for potted plants.
The loose texture of potting soil is ideal for container-grown coleus, and starting with a good mix with a slightly acidic to neutral pH of 6.0 to 7.0 is always a good idea. Make sure the pot has drainage, so the soil doesn't stay moist all the time, leading to root rot.
Coleus plants do best in damp, but not soggy, soil. The soil should not be wet all of the time, but protracted dry spells can limit the growth of the plants and cause the leaves to become brown around the edges.
Mulch will assist the soil to retain moisture for extended periods, but avoid cedar mulch, as it is harmful to coleus. Also, don't let the mulch touch the stems, since this might encourage decay and serve as a hiding place for slugs.
During warmer weather, Coleus in pots may need watering twice a day. Watering outside containers twice a day is possible. Indoor plants only require watering every two to three days or more frequently if you live in a dry area.
Humidity and Temperature
Coleus thrives in hot, humid circumstances as a tropical plant. In temperate climes, even the tiniest suggestion of frost is enough to kill the plants. Before the weather turns chilly, make sure you take cuttings for propagation.
Indoor plants should be kept away from air conditioner vents and other draughty areas. The plants will appreciate some humidity from a humidifier or a bathroom atmosphere in dry climes. Wait until the weather reaches 70 degrees Fahrenheit or above before bringing potted plants outside in the spring.
You may not need to feed coleus plants at all if you have good soil. If your soil is poor, feed your plants once a month with half-strength balanced fertilizer. If you go mild on the fertilizer, you'll get the most fantastic color from your coleus leaves.
When starting a new pot of container-grown plants, apply a slow-release fertilizer to the potting soil. After that, feed every one to two weeks with diluted liquid fertilizer. Because regular watering drains nutrients from the potting soil, container plants require more food than garden plants.
There are dozens of coleus varieties with different colors, leaf textures, and patterns available. Each year, new cultivars are created, and garden stores tend to concentrate on a few that are most popular among their consumers. To find the most unusual types, you may need to visit numerous nurseries or go online. The following are some of the types to watch for:
- Wizard series: These are tiny plants that range in size from 12 to 14 inches tall and come in various color combinations. They are well-known for being simple to raise from seed.
- Kong series: These coleus cultivars boast massive 6-inch leaves on 2-foot-tall plants. They are pretty vulnerable to direct sunlight.
- 'Black Dragon': Deep burgundy leaves with ruffled margins distinguish this uncommon species. They usually reach the elevation point of 18 inches.
- Premium Sun series: These cultivars have been bred to thrive in direct sunlight.
- Fairway series: Dwarf coleus variants with leaf designs and hues ranging from 6 to 10 inches tall.
Pinch out the growing tips when the plants are around 6 inches tall to get full, bushy plants. Pinch under the flower buds if you want the plant to focus its energy on leaves rather than flowers and seeds.
Non-pruned plants get leggy and lose their attractive shape and thick foliage. The plants may require additional sunlight if they remain leggy. This is particularly prevalent with indoor plants during the winter, so give them some extra sun or, if needed, artificial light.
Taking stem cuttings and rooting them is a simple way to reproduce favorite coleus plants.
- Cut a 4- to 6-inch long stem tip using a sharp shearing scissor, then remove all leaves from the lower half of the cutting.
- Dip the stem's end in a rooting hormone compound, then plant it in a moist potting mix with the exposed leaf nodes covered by the dirt.
- Place the container in a plastic bag, ensuring that the plastic does not contact the cutting.
- Keep the covered cutting in a bright, warm place for two to three weeks, or until new roots appear.
- Remove the plastic and place the young plant in a bright, warm location to continue to grow.
Some of the more odd varieties may be hesitant to root, so take a lot of cuttings to guarantee you have enough viable plants.
How to Grow a Coleus Plant from Seed
Modern coleus varieties are hybrids that are nearly always grown from cuttings potted up for nursery sale; however, seeds of many types can still be found. Start seeds indoors around eight to ten weeks before your last frost date if you wish to plant the coleus in the garden.
Coleus is a simple plant to grow from seed. Be patient, as it can take up to 21 days for the seeds to germinate. Warm weather will be needed for three or four weeks after seedlings appear to help them grow into fully formed plants.
- Sprinkle the tiny seeds lightly over a tray filled with potting mix, then carefully cover with dirt.
- Cover the tray with plastic wrap and place it in a sunny, warm location for two weeks or until seedlings grow.
- Remove the plastic wrap and continue to grow the seedlings in a wet environment.
- When the seedlings have two sets of true leaves, carefully transplant them into their pots and continue cultivating them until it is time to put them outside.
Coleus Potting and Repotting
Start with a large pot that the plant can grow into if you want to grow coleus in a container; otherwise, you'll be repotting this fast-growing plant before you know it. When growing coleus in terra cotta pots, it's a good idea to line the container with plastic to keep the soil moist.
Coleus is typically used as an erect "thriller" plant in the middle of a mixed container planting, surrounded by "fillers" and "spillers." Container plants are sometimes brought indoors to overwinter in colder climates.
Common Plant Pests and Diseases
Groundhogs and juvenile bunnies are the most common outdoor pests for coleus. By mid-summer, these pests will have moved on to other plants if you can protect your plants early in the season.
Diseases rarely affect Coleus until the weather becomes cool and moist. Expect to see signs of fungal infections like mildew if this happens. Keep an eye out for scale, whiteflies, and mealybugs if you're growing your plants indoors.