Overview
Coleus newtonii Briq. is a plant species belonging to the family Lamiaceae. It is a rare species and has limited distribution in the wild.
Origin and Distribution
Coleus newtonii Briq. is endemic to Thailand. It is found in the forests in northern Thailand, especially in Chiang Mai and Chiang Rai provinces. The plant grows at an altitude of 1000 to 2000 meters above sea level.
Common Names
The plant is commonly known as Salicylic-leaved Coleus. It is also sometimes referred to as Newton's Coleus, in honor of its discoverer, Alfred Newton.
General Appearance
The Coleus newtonii Briq. is a perennial herb that can grow up to 50 cm in height. It has distinctive green, rough, and hairy leaves that are oval-shaped with a pointed tip. The leaves are about 10 cm long and 5 cm wide. The inflorescence is a terminal spike that bears small flowers with a purple corolla and whitish-yellow throat. The plant's stem is cylindrical and usually green when young, eventually becoming woody and brown as the plant ages.
Uses
Coleus newtonii Briq. is primarily grown as an ornamental plant due to its attractive foliage. The plant's leaves are commonly used in traditional medicine to treat various ailments such as inflammation, fever, and cough. The plant contains various bioactive compounds, including flavonoids and terpenoids, which have shown anti-inflammatory, antimicrobial, and antioxidant activities. However, more research is needed to determine its medicinal potential.
Light Requirements
Coleus newtonii Briq. thrives in bright, filtered light conditions. Exposure to intense direct sunlight for prolonged periods may damage the plant. Therefore, it is advisable to keep the plant in an area that receives bright, indirect light throughout the day. Placing it close to a north-facing window or near bright artificial light sources can be beneficial for its growth.
Temperature Conditions
Coleus newtonii Briq. prefers moderate temperatures between 60 to 75 degrees Fahrenheit. The plant is sensitive to cold drafts and sudden temperature fluctuations. Therefore, it is crucial to keep it away from doors, windows, or air conditioning vents that can cause a rapid change in temperature. In colder climates, it is advisable to place the plant on a heating mat to maintain the required temperature.
Soil Requirements
The soil for Coleus newtonii Briq. should be loose, well-drained, and rich in organic matter. It is best to use a good quality potting mix that allows adequate airflow and drainage. The soil pH level should be between 6.0 to 7.5, which is slightly acidic to neutral. The plant is sensitive to waterlogging, so it is necessary to ensure that the soil is not too wet. Adding perlite or sand to the soil mix can improve soil drainage.
Cultivation Methods for Coleus newtonii Briq.
Coleus newtonii Briq. thrives best in well-draining soils with a pH range of 5.5 to 6.5. The plant requires partial shade to full sun exposure, and it is best grown in areas with a tropical or subtropical climate. You can start the plant from stem cuttings or seeds. When starting from seeds, ensure that the soil is moist but not waterlogged as the plant is susceptible to root rot.
Watering Needs for Coleus newtonii Briq.
Coleus newtonii Briq. requires consistent watering. The soil should be kept moist but not waterlogged as this could lead to root rot. Water the plant early in the morning or late in the evening to reduce rapid evaporation. During the hot summer months, ensure that you water the plant more frequently.
Fertilization for Coleus newtonii Briq.
Coleus newtonii Briq. requires regular fertilization to promote vibrant growth and foliage. Use a complete fertilizer with a ratio of 20-10-20. During the growing season, apply the fertilizer every three weeks. Reduce the frequency to once every six weeks during the winter months.
Pruning for Coleus newtonii Briq.
To promote compact and bushy growth in Coleus newtonii Briq., prune the plant regularly. Begin pruning the plant during the growing season once it attains a height of around six inches. Use a sterilized pair of scissors or pruning shears. You can cut back up to one-third of the plant's foliage. Prune the plant by removing the terminal buds; this encourages the growth of lateral shoots.
Propagation of Coleus newtonii Briq. Plant
Coleus newtonii Briq. is an ornamental perennial plant that is popularly grown for its attractive, multicoloured foliage. The plant is propagated through different methods that will be discussed in this section.
Propagation by stem cuttings
Stem cutting is the most common method used in propagating Coleus newtonii plants. This method requires selecting a healthy stem and cutting it below a node. The cutting should be approximately 3-4 inches long. Remove all the leaves from the bottom half of the cutting and place it in a container or pot filled with moist potting soil. Keep the soil moist, and the cutting in a shaded area until it develops roots.
Propagation by division
Propagation by division is another efficient method in which Coleus newtonii can be propagated. This method requires separating healthy side shoots from the parent plant with a sharp knife. The roots attached to the side shoot should be carefully untangled and separated from the parent plant. Then, plant the side shoot in a pot with fresh soil and keep it moist until it establishes.
Propagation by Seeds
Propagation by seeds is also possible, but it requires more time and effort than other methods. Sow the seeds in a container or tray containing fresh potting mix. Keep the soil moist and in a humid environment until germination. Once the plant has established, transplant it into a larger pot or container.
Overall, propagating Coleus newtonii Briq. is an easy process and can be achieved through stem cuttings, division or seeds. As soon as you have propagated your plant, ensure that it gets enough water and light, and soon you will have a flourishing plant.
Disease and Pest Management for Coleus newtonii Briq.
Coleus newtonii Briq. is generally a healthy plant with a low tendency to develop diseases or attract pests, especially if they are grown in the ideal conditions. However, there are still some common diseases and pests that may occur, and it is always best to prevent and manage these issues to ensure the plant's optimal growth.
Common Diseases that Affect Coleus newtonii Briq.
One of the common plant diseases that can affect Coleus newtonii Briq. is powdery mildew. This fungal disease is characterized by a white or grayish powdery coating on the foliage, and in severe cases, it can lead to leaf yellowing, stunting, and eventually death. To prevent powdery mildew, ensure that the plant is not exposed to high humidity or wet foliage. If the disease sets in, applying an organic fungicide or neem oil can help eliminate it.
Another disease that may affect Coleus newtonii Briq. is root rot. Root rot is caused by waterlogged soil or poor drainage, leading to the roots' rotting. This disease's symptoms include yellowing or wilting plants, stunting, and blackened roots. To prevent root rot, ensure proper drainage of the soil, and avoid overwatering. If root rot sets in, prune out the affected roots and repot the plant in fresh soil.
Common Pests that Affect Coleus newtonii Briq.
One of the common pests that affect Coleus newtonii Briq. is spider mites. These tiny pests cause stippling on the leaves and can cause defoliation in severe cases, leading to stunted growth and plant death. To manage spider mites, increase humidity levels around the plant, wash the leaves with a steady stream of water, and use insecticidal soap or neem oil.
Another common pest that may attack Coleus newtonii Briq. is mealybugs. These pests are characterized by sticky, whitish secretions and a cotton-like mass attached to the foliage or stems, causing stunting, yellowing, and eventually death in severe cases. To manage mealybugs, remove the affected parts of the plant, isolate it from other plants to prevent infestation, and use insecticidal soap or neem oil.
In conclusion, preventing and managing diseases and pests on Coleus newtonii Briq. is crucial in ensuring a healthy and vibrant plant. Observing good cultural practices and applying organic and natural remedies can help to keep the plant healthy and reduce the need for synthetic pesticides and fungicides.
