Coleuse Plant

                        Introduction

                                         

Coleuses are that types of plants which have colorful variegated leaves, typically with sharp contrast between the colors; the leaves may be green, pink, yellow, black (a very dark purple), maroon, and red (somewhat resembling the unrelated caladium). They are best known for their bright colors, and varieties. Coleuses are typically grown as ornamental plants- may be in the garden or in a container as a house plant.

             

              Scientific classification of Coleus

                              Kingdom: Plantae

                                 Unmarked: Angiosperms

                                     Unmarked: Eudicots

                                        Unmarked: Asterids

                                           Order: Lamiales

                                               Family: Lamiaceae

                                                  Genus: Solenostemo

                                                     Species: S. autranii

                                                               S. rotundifolius

                                                               S. scutellarioides

                                                               S. shirensis

                                                               S. pumilus

            .

           Solenostemon is a genus of perennial plants, native to tropical Africa, Asia, Australia, the East Indies, the Malay Archipelago, and the Philippines. They are commonly known as Coleus, a name which derives from an earlier classification under the genus name Coleus, species of which are currently included in either Solenostemon or another genus, Plectranthus. Although these plants are a member of the nettle family, they are a mint. They do not have the stinging properties of the nettle.

                                                                                                    

                     Varieties of Coleus

       

Cause of varieties

          Coleuses are best known for their bright colors, and variety of foliage forms. The foliage color however is often enhanced when they are grown in the shade. Most Coleus plants will survive full sun exposure. The intensity of light which the plant receives will also have a direct bearing on the intensity of the foliage coloring. Some varieties may produce their best color in light shade, while others look best in bright lighting. Florescent "grow' lights seem to bring out even more intense and vibrant coloring.

Most popular varieties

They are widely available in a variety of sizes ranging from bedding plant "six packs" to massive specimen sized hanging house plants. Sometimes it is hard for gardeners to find just the right colors for their garden landscapes. The small starter plants may seem bland and fairly colorless when compared to the larger specimens. The lower growing dwarf varieties (6-12 inch) will create a colorful border or the taller (3 feet) types as a dramatic background planting. The sheer numbers of coleus hybrids available today are amazing - so here are some of the best, most colorful and most popular coleus plants. These are some of the most popular choices. There are highly textured coleus plants with highly cut foliage. Others have brightly colored variegation, while some plants have more muted tones.

Textured Foliage Coleus Plants or with Fine Cut Leaves

1.  Kiwi Fern Coleus - The long leaves are dark maroon in color with chartreuse edges.  Highly textured leaves make both the color and shape of these leaves a unique accent in the garden.

2.  Black Dragon Coleus - Dark burgundy leaves have slightly paler centers, but   the attractive feature of the coleus plant has tight, wavy edges that are ornamental.  

3.  Kong Series; Kong Rose - A tri-colored coleus plant with huge leaves that have wide, lime green edges, reddish centers and brighter pink veining in the center.

         

                           Kiwi fern            Black dragon     Kong Series

Coleus Plants with Variegated, Lance-Shaped Leaves

1.  Defiance Coleus - This coleus has more classic shaped leaves. The leaves are red with wide, yellow-green edges that serve to contrast beautifully while still serving as a good backdrop for other flowers.

2.  Dip in Wine Coleus - The foliage of this coleus is wine red in color with bright green centers and the leaves tend to be slightly more rounded in shape than a traditional coleus plant. This is an award-winning cultivar.

3.  Freckles Coleus - Bright yellow leaves have maroon splotches and freckles on them that sometimes appear lighter, almost orange in tone. A great cultivar to add bright highlights to a shade garden spot.

                                   Defiance Coleus    Dip in Wine Coleus       Freckles Coleus

Coleus Plants with Muted or Multi-Colored Foliage

1.  Texas Parking Lot or Alabama Sunset Coleus - Bright green leaves slowly deepen into a muted maroon color as they age creating a unique contrast of color between the green and red colored leaves. Seedlings do not grow true so gardeners will need to take cuttings.

2.  Tilt-a-Whirl Coleus - The color of this coleus is highly unusual with nearly orange colored leaves that add a touch of fall like color to the spring and summer garden. Bright green or yellow centers to the leaves add a strong accent color to the plant making it a great choice for containers. 

                                               

    Texas Parking Lot or Alabama Sunset Coleus                            Tilt-a-Whirl Coleus

More Varieties

        Coleuses have huge varieties. Most of them are given below:

 Cultivation

 

 

 

Species/variety selection

Although Coleuses are technically a "tender perennial" (even the slightest frost will cause them to die), they are most often considered to be an annual plant by growers and seed producers. Many cultivars of the Southeast Asian species Solenostemon scutellarioides have been selected for their colorful variegated leaves, typically with sharp contrast between the colors.

     

New cultivars with varieties of colors are constantly being made.

Weather

 The plants grow well in moist well-drained soil, and typically grow 0.5-1 m tall, though some may grow as tall as 2 meters. They are heat-tolerant, though they do less well in full sun in subtropical areas than in the shade. In mild areas (no snow in winter), plants can usually be kept as perennials if well managed.

     

Whereas cultivation in colder areas, they are often grown as annuals as they are not hardy and become leggy and unattractive with age. Though this is usually resolved by pinching back growing tips to encourage bushing. In bright hot areas, the colors of the plant will typically be more intense in shaded areas than in full sun, and the plants will require less water there.                     

 

Maintenance

 Coleus also make low-maintenance houseplants, and can often be propagated by clipping a length of stem just below the leaves and putting the stem in water to root. The plant's flowers grow on a stem above that stem's leaves, and tend to be purple and quite small in comparison to the leaves. The plant is not generally grown for its flowers, as it promotes stem elongation. By removing the flower spikes as they develop, and keeping the plant pinched back, the Coleus can be kept in a perennial state for several seasons.

        

Coleus plants may be grown in the garden in bright, indirect light, or in partial shade. Coleus plants are also quite striking when they are planted in a container, and grown as a house plant.

 

 

                 Objectives of cultivation

Coleus as a house plant

         A Coleus will make a nice house plant as long as it receives sufficient light and food. The Coleus should be planted in a light, quick draining, and commercial potting soil. It should be placed where it will receive several hours of bright light (south window) each day, or should be provided artificial "grow" lighting for best leaf color, and fullest plant. Coleus plants will adapt to a wide range of temperatures above 55 degrees, but will grow best when they are kept between 70 and 85 degrees. The soil should be kept evenly moist, but never soggy. Coleus plants should be fed monthly, with a diluted (50% mix) liquid house plant fertilizer. Flower buds must be pinched off as soon as they develop to prevent the plant from producing seeds. The flower spikes are very insignificant. Once a Coleus is allowed to go to seed, it has completed its life objective, and it will usually die. Pinching may also be necessary to prevent leggy growth. Any time that the tip growth is removed, the plant's energy will be diverted to the lateral side growth, creating a much bushier plant.  

      

Coleus plans are very durable, so the plant can be cut back severely if needed (almost back to the soil level).

Coleus in the garden

        Coleus plants should not be set into the landscape until the minimum outdoor temperature is 50 degrees F. Although Coleus plants will usually survive in full sun, the foliage color tends to intensify in light shade when they are grown outdoors. They should be planted 12 inches apart in rich, moist, well-drained soil with a neutral or slightly alkaline pH & fed monthly with a liquid all purpose (10-10-10) fertilizer. Then should be pinched the center stems out when the plants are 4 to 6 inches tall to induce bushier growth, and to be sure to pick off the flower spikes as they form. If the soil is allowed to dry out, the foliage will wilt, but normally will recover quickly when additional water is provided. Plants should be watered thoroughly at planting time, and then the entire bed mulched to conserve moisture. The mulch will also help to heat up, and retain the heat in the soil, thereby helping the plants to get established in their new home.

                        

Mealy bugs, aphids and whitefly, as well as slugs and snails should be watched out.      

                                                 Propagation  

          Coleus plants are durable and easy to grow. There are two ways to propagate Coleus. They are- Seed & Cutting.

                                                     

Seed

         Seeds are inexpensive and easily obtainable. To germinate, simply seeds should be sprinkled on the surface soil and pressed down. Seeds need light to germinate, so it should be avoid covering the seeds. If the intent is to grow Coleus as a house plant, the seed may be sown indoors, at any time of the year. If the seedlings are destined for a garden location, they should be started indoors, at least 10 weeks before the last expected frost, so that the plants will be well developed when it is time to plant them outdoors. Coleus seeds are very small. They should be sown onto a layer of moistened, sterile potting soil in a shallow tray, and then covered with a thin layer of fine soil. The tray should be covered with a pane of glass or sheet of plastic to retain moisture, until the seeds have sprouted. After that the tray is kept in a warm (65-75 degree F.), bright (not full sun) place. When the seedlings are large enough to handle easily, they should be thinned out and transplanted into individual pots. Seedlings should always be held by a leaf, never by the stem!

        

When all danger of frost is past the plants may be set out in the garden. Once the seedlings reach a certain point in their growth, they will develop additional coloring and foliage characteristics.

Cutting

       Propagating Coleus by cuttings is equally as easy. First it should be created a clone of the chosen Coleus by taking softwood stem cuttings at any time of the year. Using a sharp clean knife the stem should be cut just below a leaf node. It should be removed the lowest leaves, dip the cut end into a rooting hormone and insert it into some fresh, sterile potting soil. These cuttings will be ready to use as a bright garden accent by early June.

              

They will also root quickly when set in moist sand or vermiculite, or even in a glass of room temperature tap water.

                                     

                                         Diseases

1. Downy mildew- It is one kind of disease that can affect coleus. This mildew appears on the leaves making the plant look dirty because it is brown in color. The organism is called Peronospora sp. and can also result in curled and twisted leaves. Sometimes symptoms are not found on leaves which make      the disease harder to control.

                                

2.  Impatiens necrotic spot virus- It is another disease which causes brown or yellow spots on leaves, rings, black or brown stem discoloration, and brown leaf veins, ultimately resulting in plant death. The disease is spread by an insect called a thrips that carries the virus from an infected plant to an uninfected plant. It only takes a few of these insects to infect a whole greenhouse.

                        

                                  

                                    Psycho-activity

           Coleus Blumei has very mild relaxing and hallucinating effects. Coleus has not been explored very much but has been known to have been used by the Mazatec indians.

                                     Conclusion

Coleus plants are very charming & pretty to their colorful appearance. So, they are most popular as ornamental plants. They are also easy to propagate & cultivate. So, plant breeders love to create new, brightly colored varieties of Coleus plants for container gardeners or home landscaping.

  

    Since coleus can hybridize and sport easily, there are many named (and unnamed) cultivars available for gardeners to use, Combine coleus with other coleus plants, or create unique shade containers by adding to fountain grass, hostas, false, forget-me-not, or bleeding heart.

                 Procedure of the project

I have gone to nursery in front of Karjon hall & Dhaka College for observing Coleus plants. I have taken some photos of them. Then I have searched internet & downloaded information about coleus. With the help of these photos, information & observation, I completed this project work.

                                   References

                                                    Karjon hall nursery

                                              Dhaka college nursery                                                                                                                      

                                               www.yahoo.com

                                             www.google-image.com