Overview
Tanacetum obtusum Thunb., commonly known as the round-leaf tansy or Japanese yomogi, is a plant species belonging to the daisy family (Asteraceae). The plant is native to Japan and is widely cultivated in China, where it is commonly used in traditional medicine.
General Appearance
The Tanacetum obtusum Thunb. plant is a perennial herb that typically grows up to 1 meter in height. It has a woody stem that is covered in fine hairs, and its leaves are arranged alternately along the stem. The leaves are round in shape, with toothed edges, and have a greenish-grey color on top and white undersides. The plant produces small yellow flowers that grow in clusters at the tips of the stems.
Common Names
Tanacetum obtusum Thunb. is known by a variety of common names, including the round-leaf tansy, Japanese yomogi, and oriental tansy. In China, it is known as Juhua yomogi or Bai juhua.
Uses
Tanacetum obtusum Thunb. is commonly used in traditional Chinese medicine to treat a variety of ailments, including fever, malaria, and inflammation. The plant contains various bioactive compounds, including flavonoids and terpenoids, which have been shown to have anti-inflammatory and antioxidant properties. Additionally, the plant has been used in Japan to make mochi, a traditional rice cake, and as a flavoring in various foods and beverages.
Light Requirements:
The plant Tanacetum obtusum Thunb. requires full sun or partial shade. Therefore, it grows well in sites where it can obtain sunlight for at least six hours per day. It can also tolerate a certain degree of shade, but excessive shade may cause slow growth and poor flower production.
Temperature Requirements:
The plant Tanacetum obtusum Thunb. prefers moderate temperatures with a temperature range between 15 °C to 25 °C. It can tolerate both high and low temperatures. However, it is vulnerable to frost and requires protection or be brought indoors during the winter season.
Soil Requirements:
The plant Tanacetum obtusum Thunb. thrives in fertile, well-drained soil. It can grow well in a wide range of soils, including sandy, loamy, and clay soils, but it grows best in well-draining, slightly alkaline soil with a pH range of 6.0 to 7.5. The soil should also be rich in organic matter, and the plant may require regular fertilization to promote growth and maintain healthy foliage.
Cultivation Methods for Tanacetum Obtusum Thunb.
Tanacetum obtusum Thunb. requires a well-draining soil mix that is slightly acidic. The plant is best grown in full sunlight, but it can also grow in partial shade. The ideal temperature for growing this plant ranges from 20 to 25 degrees Celsius.
The seeds should be sown indoors during early spring in a seed tray. After germination, the seedlings should be transplanted to individual pots and grown in a greenhouse or indoors until the risk of frost has passed. The plant can also be propagated through cuttings during early summer and planted in individual pots before transplanting them outside.
Watering Needs for Tanacetum Obtusum Thunb.
Tanacetum obtusum Thunb. prefers moist soil but can tolerate periods of drought. Overwatering can be harmful to the plant's growth. Therefore, it is recommended that you water the plant thoroughly when the soil becomes dry to the touch. During hot and dry weather, the plant may require frequent watering to maintain its growth.
Fertilization for Tanacetum Obtusum Thunb.
Tanacetum obtusum Thunb. requires a balanced fertilizer to encourage healthy growth. It is recommended that you use a slow-release granular fertilizer during the spring. The fertilizer should be mixed into the soil around the base of the plant and watered in thoroughly. Avoid applying too much fertilizer as it can damage the plant.
Pruning Tanacetum Obtusum Thunb.
To encourage the growth of new leaves and prevent the plant from becoming leggy, Tanacetum obtusum Thunb. should be pruned during the summer. It is recommended that you cut back the plant to half of its height, removing any dead or damaged leaves. This will promote the growth of new foliage, making the plant look more healthy and vibrant.
Propagation of Tanacetum obtusum Thunb.
Tanacetum obtusum Thunb., commonly known as Japanese yarrow or Korean tansy, is a flowering perennial plant that belongs to the Asteraceae family. Propagation of Tanacetum obtusum Thunb. can be done through several methods, including seed propagation, division of mature plants, and stem cuttings.
Seed Propagation
Seed propagation is the most common method for propagating Japanese yarrow. The seeds can be sown directly in the ground during the fall or early spring. The soil should be well-draining and moist for good germination. Cover the seeds lightly with soil and keep the soil consistently moist until germination occurs, which usually takes about two to three weeks. Once the seedlings have grown to a reasonable size, they can be transplanted to their permanent location.
Division of Mature Plants
Division of mature plants is another way to propagate Tanacetum obtusum Thunb. This method is best done in the spring when new growth is beginning to emerge. Dig around the outer edges of the plant and pry it out of the soil, making sure to keep as much of the root system intact as possible. Divide the plant into smaller sections, making sure each section has new growth and a good amount of roots. Transplant the divided sections to their new location and water thoroughly.
Stem Cuttings
Propagation of Tanacetum obtusum Thunb. can also be done through stem cuttings. Take stem cuttings from the plant during the growing season, making sure to choose mature, healthy stems. Cut the stems into sections of about 6 inches, making sure each section has at least one node. Remove all leaves except for the top two or three. Dip the bottom end of the cutting in rooting hormone and plant it in a container with well-draining soil. Water the cutting thoroughly and cover it with a plastic bag to retain moisture. Place the container in indirect sunlight and keep the soil consistently moist until roots begin to form, which usually takes about four to six weeks. Once the roots have formed, the cutting can be transplanted to its permanent location.
Disease and Pest Management for Tanacetum Obtusum Thunb.
Tanacetum obtusum Thunb., also known as Japanese Tansy, is a robust perennial herb with several medicinal properties. The plant is mainly used for its antiviral, antioxidant, and anti-inflammatory benefits. However, like other plants, Japanese Tansy is vulnerable to pests and diseases that can affect its growth rate, yield, and medicinal value. Proper management is, therefore, necessary to control these pests and diseases.
Common Diseases Affecting Tanacetum Obtusum Thunb.
One common disease that affects Japanese Tansy is powdery mildew, which is caused by the fungi Erysiphe cichoracearum. Powdery mildew appears as white or gray powdery substance on leaves, stems, and flowers of the plant. It can stunt plant growth, reduce yield, and lower the medicinal value of the plant.
Another common disease that affects Japanese Tansy is leaf spot, which is caused by the fungi Septoria tussilaginis. Leaf spot appears as small, dark, and water-soaked spots on the leaves, which eventually become large and yellow. Infected leaves may fall prematurely, which affects the yield and growth of the plant.
Pest Management
One of the most common pests that affect Japanese Tansy is spider mites. Spider mites are tiny and suck the sap from leaves, which causes yellowing of the plant. They may also produce sticky webbing that affects the plant's respiration and photosynthesis. To manage spider mites, it is essential to regularly monitor the plant and remove any infested parts. A blast of water or neem oil spray can help control spider mites.
Another common pest that affects Japanese Tansy is aphids, which are small insects that suck sap from plant tissues. Aphids can cause yellowing, curling, and stunted growth of the leaves, stems, and flowers. To manage aphids, you can use insecticidal soap or neem oil. You can also attract natural predators such as ladybugs, lacewings, and parasitic wasps.
Disease Management
To manage powdery mildew, it is essential to maintain proper plant spacing and air circulation. You can also apply fungicides to control the spread of the disease. However, it is essential to observe proper timing and dosage to prevent phytotoxicity.
For leaf spot disease, it is necessary to remove infected leaves and destroy them. You can also apply copper-based fungicides to control the spread of the disease. Remember that using fungicides can cause a negative impact on the environment. Therefore, it is necessary to follow instructions and observe precautions in handling and application.
In conclusion, disease and pest management are crucial in maintaining the health and productivity of Tanacetum obtusum Thunb. Proper monitoring, timely intervention, and appropriate management strategies can help you control pests and diseases that may affect the growth and yield of your Japanese tansy plant.
