Origin
Bupleurum falcatum, commonly known as Chinese thorowax or simply thorowax, is a plant species that belongs to the family Apiaceae (carrot family). The plant is native to China, Korea, and Japan, and has been widely cultivated throughout Asia and Europe for its medicinal benefits.
Common Names
Aside from Chinese thorowax and thorowax, this plant is also commonly referred to as hare's ear root, sickle-leaf hare's ear, Bupleurum, and Chai Hu in traditional Chinese medicine.
Uses
The roots of Bupleurum falcatum are the most commonly used part of the plant in traditional medicine. It has been used for centuries in Chinese medicine to treat a variety of conditions including fever, liver diseases, respiratory infections, and digestive disorders. It is also believed to have anti-inflammatory and antioxidant properties.
In recent years, Bupleurum falcatum has gained attention in Western countries for its potential use in cancer treatment. Studies have shown that its active compounds have anticancer effects and can enhance the efficacy of chemotherapy drugs.
General Appearance
Bupleurum falcatum is a perennial plant that can grow up to 1.5 meters tall. Its stem is round and hollow and can display branches near the top. The leaves are alternate and measure between 5-12 cm in length, with the blades being lance-shaped and falcate (curved like a sickle) with serrated margins. The flowers grow in umbels that can measure up to 10 cm in diameter, and their color may range between greenish-yellow, yellowish or yellowish-white. The plant's fruits are elliptic, 2-3 mm long, and visible from September to November.
Light Requirements
Bupleurum falcatum requires full sun to part shade to grow optimally. It can also tolerate light shade, but it may affect flowering and overall growth. Therefore, grow the plant in a location that gets at least six hours of direct sunlight each day.
Temperature Requirements
Bupleurum falcatum is a hardy plant that can tolerate a wide range of temperatures. It grows well in USDA hardiness zones 4 to 9, which cover a temperature range of -30 to 30 degrees Celsius (-22 to 86 degrees Fahrenheit). The ideal temperature for Bupleurum falcatum is around 20 degrees Celsius (68 degrees Fahrenheit). If the temperature exceeds 30 degrees Celsius (86 degrees Fahrenheit), the plant may require shade during the hottest part of the day.
Soil Requirements
Bupleurum falcatum prefers well-draining soil that is rich in organic matter. Sandy and loamy soil types are suitable for this plant. However, it can also grow in clay soil if you improve the drainage. A pH range of 6.0 to 7.5 is ideal for this plant. In case the soil is too acidic, add lime to raise the pH level, and for alkaline soil, add sulfur.
Cultivation Methods
Bupleurum falcatum is a plant that is relatively easy to grow, requiring minimal attention. It can be propagated through seeds that should be sown directly in the soil that is well-draining. A location that gets full sunlight or partial shade is ideal. The soil pH should range between 6.0 and 8.0, and it should be moderately fertile. The soil should also be kept moist but not waterlogged.
Watering Needs
Bupleurum falcatum requires consistent and regular watering, but it must not be overdone. To maintain the soil's moistness, irrigation should be done regularly, especially in the warm and dry months. In case of excessive rain, the soil drainage should be checked to prevent waterlogging which could cause the roots to rot. Watering in the morning is the best time to water this plant.
Fertilization
Bupleurum falcatum can grow in a variety of soils, but for best results, the soil should be moderately fertile. You may amend the soil with compost or organic matter before planting to improve the soil quality. The plant should be fertilized during the growing season to supply the extra nutrients it needs to thrive. A balanced fertilizer should be used, with an equal ratio of nitrogen, phosphorus, and potassium.
Pruning
Bupleurum falcatum does not necessarily require pruning, and any pruning should be limited to removing dead or damaged growth only. If you intend to propagate, the seeds can be collected after flowering and sown again. To maintain a neat appearance, the plants should be deadheaded regularly. However, if the plant has grown too large, it can be cut back in late fall or early spring.
Propagation of Bupleurum falcatum
Bupleurum falcatum belongs to the Apiaceae family and is a perennial herbaceous plant grown for ornamental and medicinal purposes. It is native to Asia and is also known as Chinese thoroughwax or hare's ear.
Propagation by Seeds
The most common method of propagating Bupleurum falcatum is through seeds. The optimal time for sowing seeds is in the spring when the soil temperature is between 15-18°C. The seeds require sunlight to germinate, and it takes about 2-3 weeks for them to sprout.
First, loosen the soil and remove any weeds or debris. Then, scatter the seeds on the soil surface and lightly press them into the soil. Be sure to keep the soil moist until germination occurs. Once seedlings appear, thin them out to about 30 cm apart to promote healthy growth.
Propagation by Division
Another way to propagate Bupleurum falcatum is through division. This method involves separating the plant into smaller sections and then planting them individually.
To divide the plant, dig up the entire root system and gently separate the clumps into smaller sections. Each section should have a healthy root system and several stems. Plant the sections in a well-draining soil mix and water thoroughly.
Make sure to keep the newly planted divisions well-watered until they become established.
Propagation by Cuttings
Bupleurum falcatum can also be propagated through cuttings. It is best to take cuttings during the summer when the plant is actively growing.
To propagate through cuttings, select a healthy stem and make a cut about 10 cm from the tip. Remove the lower leaves and dip the cut end in rooting hormone. Then, plant the cutting in a well-draining soil mix and water thoroughly.
Make sure to keep the cutting in a warm and humid environment until it establishes roots and begins to grow.
Disease and Pest Management for Bupleurum falcatum
Bupleurum falcatum, also known as sickle-leaved hare's ear, is an herb that is native to Asia and Europe. While considered a hardy and disease-resistant plant, there are still a few diseases and pests that can affect it. Here are some common issues and ways to manage them:
Diseases
Root Rot: Root rot is caused by a fungus that thrives in overly wet soil. It can cause wilting, stunted growth, yellowing leaves, and eventual death of the plant. To manage root rot, ensure the soil is well-draining, and avoid overwatering the plant. Remove any affected plants and replace with healthy ones.
Leaf spot: Leaf spot is characterized by light brown spots on the leaves, which can enlarge and eventually cause the leaves to fall off. It is caused by fungal infections that thrive in moist conditions. To manage leaf spot, avoid watering the foliage, and remove affected leaves and destroy them. Applying fungicides can also help prevent the spread of the disease.
Pests
Aphids: Aphids are small, soft-bodied insects that feed on the sap of plants. They can cause stunted growth, curled leaves, yellowing, and distortion of leaves and stems. Spray the plant with a strong stream of water to dislodge the aphids. Applying insecticidal soap or neem oil can also help get rid of aphids.
Cabbage Worms: Cabbage worms are the larvae of the white butterfly. They feed on the leaves, causing large holes and weakening the stems. Hand-pick any visible cabbage worms off the plant. Applying Bacillus thuringiensis (Bt) can also help control cabbage worms.
Overall, Bupleurum falcatum is a hardy plant that requires minimal care. Proper watering, fertilization, and regular pruning can help keep it healthy and disease-free. By being proactive and identifying any issues early-on, you can prevent most diseases and pest infestations from causing long-term damage to your plants.
