General Description
Bidens denudata Turcz. is a species of flowering plant that belongs to the family Asteraceae or sunflower family. It is native to East Asia and can be found in China, Japan, Korea, and Taiwan. This plant is also known by several common names such as yellow cosmos, Hairy Beggarticks, and zheng gan cao.
Appearance
The Bidens denudata Turcz. plant grows up to two meters tall and has erect or ascending branches. It has a shallow root system and hairy, stalked leaves that are 4-6 cm long. The flowers of this plant are yellow and are usually found in small clusters at the end of the branches. The flower heads are about 1.5-2cm long and have 12-20 ray florets as well as numerous disc florets. The plant blooms from August to October.
Uses
Bidens denudata Turcz. has a long history of use in traditional Chinese medicine to treat various ailments including coughs, colds, fever, and intestinal ailments. It is known for its antipyretic, anti-inflammatory, and analgesic properties. The whole plant is used in medicine, including the roots, stems, leaves, and flowers. In some cultures, it is also believed to be effective in treating snakebites. Additionally, it can be used for ornamental purposes and is often planted in gardens or grown in containers.
Light Requirements
Bidens denudata Turcz. thrives in areas with full sun exposure but can tolerate partial shade. It requires at least 6 hours of direct sunlight per day for optimal growth and blooming. Shaded areas can promote stem elongation and decrease flower production.
Temperature Requirements
This plant prefers a warm and humid environment and is sensitive to frost and cold temperatures. The ideal temperature range for growth and flowering is between 18°C to 30°C. Temperatures below 10°C can lead to damage or death of the plant. High temperatures above 35°C can result in overheating and wilting.
Soil Requirements
Bidens denudata Turcz. can grow in various soil types, including sandy, loamy, and clayey soils. However, it thrives in well-drained, loose, and fertile soils. The soil pH should be in the range of 6.5 to 7.5. The addition of organic matter, such as compost or aged manure, can improve soil structure and fertility.
Cultivation
Bidens denudata Turcz., commonly known as the Kahili bidens, is a hardy perennial that belongs to the Asteraceae family. It is easy to cultivate and care for, making it a popular choice among garden enthusiasts.
The plant thrives in full sun to partial shade and is not particular about soil type. However, it prefers well-drained, moist soil conditions.
Sow the seeds of the Kahili bidens directly in the garden during the spring or fall seasons. Alternatively, you can start the seeds in containers and then transplant them to the garden once they have established roots.
Watering
Kahili bidens requires regular watering, especially during dry spells. Water your plants deeply and often enough to ensure that the soil is always moist, but not waterlogged, as root rot can occur.
Water the plants early in the day to prevent moisture from collecting on the leaves, which can lead to fungal and bacterial diseases.
Fertilization
The Kahili bidens plant does not require a lot of fertilizer. However, you can incorporate some slow-release granular fertilizers into the soil during the planting process to give the young plants a good start.
You can also use a balanced liquid fertilizer to feed the plants during their growing season. However, do not apply too much fertilizer as it can lead to excessive foliage growth, reducing the number of flowers produced.
Pruning
Prune the Kahili bidens plant regularly to encourage bushier growth and promote more flowers. You can deadhead the spent flowers by cutting the flowering stems back to where they join the main stem.
Cut back the plant's foliage by one-third or half in the fall once it has finished flowering. Doing so can help prevent the plant from becoming too leggy and will promote new growth in the spring.
Propagation of Bidens denudata Turcz.
Bidens denudata Turcz. is a hardy, herbaceous perennial plant that can be propagated via several methods. It belongs to the family Asteraceae, and it is commonly called the "Beggar's Tick" or "Shuizhuyu" in China. The plant has several medicinal properties and is therefore cultivated in many parts of the world.
Propagation by Seeds
Propagation of Bidens denudataTurcz. can be done via seeds. The best time to collect the seeds is when the flower heads are dry. The plant produces achenes - dry, hard seeds that are similar to ticks. The seeds can be planted immediately, or stored in a cool, dry place. Before sowing, the seeds should be soaked in water for 24 hours. The soil should be fertile and well-drained, with a pH of 5.5 to 7. The seeds should be sown at a depth of 1 cm and kept moist. Germination usually occurs in 7-14 days.
Propagation by Cuttings
Bidens denudata Turcz. can also be propagated via stem cuttings. The best time to take cuttings is in the spring when new growth begins. The cuttings should be 10-15 cm long, and the leaves on the bottom half of the cutting should be removed. The cuttings should be dipped in rooting hormone, planted in a well-draining potting mix, and kept moist. After a few weeks, roots should appear, and the cuttings can be transplanted into individual containers.
Propagation by Division
Bidens denudata Turcz. can also be propagated via division. The best time to divide the plant is in the spring when new growth begins. The plant should be dug up, and the root ball should be divided into several sections using a sharp knife. Each section should have at least one root and several shoots. The divided sections should be planted in well-draining soil, kept moist, and protected from direct sunlight until they are established.
Disease Management
Bidens denudata Turcz. is generally a hardy plant, but it can still be susceptible to disease. Some of the most common diseases that can affect the plant include:
- Leaf spot: This is caused by fungal pathogens that attack the leaves of the plant, causing yellowing, browning, and eventually, necrosis. This disease can be managed by applying fungicides and removing and destroying infected leaves.
- Root rot: This is a fungal disease that affects the roots of the plant, causing stunted growth, wilting, and eventually, death. To manage root rot, avoid overwatering and ensure good drainage. Additionally, treating the soil with fungicides can help control the disease.
- Botrytis blight: This is caused by a fungus that attacks the flowers and leaves of the plant, causing them to become covered in a gray mold. To prevent botrytis blight, avoid overwatering and ensure good air circulation around the plant.
- Virus infections: Several viruses can infect Bidens denudata Turcz., causing symptoms such as stunted growth, yellowing, and mottling of the leaves. Unfortunately, there are no cures for viral infections, and infected plants should be removed and destroyed to prevent the spread of the virus.
Pest Management
Bidens denudata Turcz. can also be attacked by a range of pests, including:
- Aphids: These small insects can suck the sap from the leaves of the plant, causing them to curl and distort. To manage aphids, you can use insecticidal soaps or oils, or introduce natural predators like ladybugs.
- Spider mites: These are tiny pests that can cause leaves to discolor and become covered in fine webs. To manage spider mites, you can use insecticidal soaps or oils, or increase the humidity around the plant to discourage their growth.
- Caterpillars: The larvae of some moth and butterfly species can eat the leaves of the plant. To manage caterpillars, you can handpick them off the plant or use biological controls like Bacillus thuringiensis (Bt).
- Slugs and snails: These pests can feed on the leaves and stems of the plant, leaving behind slime trails. To manage slugs and snails, you can use copper barriers around the plant, or use slug baits that contain iron phosphate, which is less hazardous than traditional chemical formulations.
