Origin and Common Names
Bidens bipinnata L. is a species of flowering plant in the family Asteraceae. It is native to North America and can be found throughout the United States and Canada, as well as parts of Mexico. This plant goes by many common names including Spanish needles, butterfly needles, cobbler's pegs, and devil's sticktight.
Appearance
Bidens bipinnata L. has a slender stem that grows up to 1.5 meters tall. Its leaves are bipinnate, meaning they have two levels of leaflets, and are up to 15 centimeters long. The plant produces yellow flowers that are about 1 centimeter wide and have a cone-like center. The flowers bloom from June to September.
This plant is characterized by its small, hooked seeds called achenes. The achenes are covered in barbs that stick to clothing or animal fur, allowing the plant to spread its seeds.
Uses
Native Americans have used Bidens bipinnata L. for its medicinal properties. It has been used as a diuretic, astringent, and to treat gastrointestinal and respiratory issues. The plant has also been used as a dye for baskets and other materials.
In addition to its medicinal properties, Spanish needles are a popular food source for wildlife such as rabbits and deer. The plant's flowers also attract butterflies and other pollinators.
Light Requirements
Bidens bipinnata thrives in full sun to partial shade, requiring at least 4-6 hours of direct sunlight daily. Insufficient light can adversely affect its growth, leading to leggy plants or reduced flowering.
Temperature Requirements
Bidens bipinnata grows best in warm temperatures ranging from 68-82°F (20-28°C), though it can tolerate temperatures as low as 50°F (10°C). It is not frost tolerant and will not survive in freezing temperatures.
Soil Requirements
This plant prefers well-draining soil that is moist and fertile. It can tolerate different soil types, ranging from sandy to clayey soils, as long as they are enriched with organic matter. The ideal pH range for growth is 6.0-7.5. Bidens bipinnata can tolerate drought and nutrient-poor soils, but it may affect its overall health and growth.
Cultivation methods
Bidens bipinnata L. can be grown from seeds or cuttings. The best time to plant this plant is in the early spring when the soil has warmed up, and the chance of frost is minimal. This plant prefers full sun but can tolerate partial shade. It is recommended to plant Bidens bipinnata L. in well-drained soil with a pH between 5.5 and 7.0.
Watering needs
Bidens bipinnata L. requires regular watering, especially during the hot summer months. However, overwatering should be avoided as it can lead to root rot and other fungal diseases. The soil should be allowed to dry out slightly between watering to ensure that the plant does not suffer from waterlogging.
Fertilization
Bidens bipinnata L. benefits from regular fertilization during the growing season. A 10-10-10 fertilizer can be applied every two to three weeks. Be sure to follow the application instructions on the package to avoid over-fertilization, which can lead to burnt foliage and root damage.
Pruning
Bidens bipinnata L. does not typically require pruning. However, deadheading spent flowers can help promote additional blooming. Pruning may also be necessary to remove damaged or diseased foliage.
Propagation of Bidens bipinnata L.
Bidens bipinnata L. is a plant that belongs to the family Asteraceae and is commonly known as Spanish needles, Devil's beggarticks, or butterfly needles. It is an annual or perennial plant that can grow up to 3 feet tall and has showy yellow or white flowers.
Propagation methods
Bidens bipinnata L. can be propagated through seeds or stem cuttings.
Propagation through seeds
The seeds of Bidens bipinnata L. can be easily collected from the mature plant and used for propagation. The seeds are small, brown, and have a bristly texture.
To propagate through seeds, the following steps can be followed:
- Collect the seeds from the mature plant and allow them to dry for a few days.
- Sow the seeds in a well-draining soil mixture with good fertility. The ideal time for sowing seeds is in the spring when the temperature is warm.
- Water the soil, and cover the seeds with a thin layer of soil mix. The seeds should be spaced at least 6 inches apart.
- Place a plastic cover or a cloche over the container to create a humid environment, which will help in germination. Alternatively, the container can be placed inside a plastic bag to create a mini-greenhouse effect.
- Keep the container in a bright location, but away from direct sunlight and maintain a consistent level of moisture in the soil.
- The Bidens bipinnata L. seeds will germinate in about 7 to 14 days.
- After the seedlings have grown to about 2 inches tall, they can be transplanted to their permanent location.
Propagation through stem cuttings
Propagation of Bidens bipinnata L. through stem cuttings is a faster method of propagation compared to seed propagation. Stem cuttings are taken from established plants to create new plants.
To propagate through stem cuttings, the following steps can be followed:
- Take a 4 to 6-inch stem cutting from a healthy Bidens bipinnata L. plant, preferably in the spring when the plant has started growing.
- Cut the stem just below a node, and remove any leaves from the lower part of the stem, leaving only the top set of leaves.
- Plant the stem cutting in a well-draining soil mix and water the soil thoroughly.
- Cover the container with a plastic bag to create a mini-greenhouse effect and maintain a consistent level of moisture in the soil.
- Keep the container in a bright location, but away from direct sunlight.
- The stem cutting will develop roots in about 3-4 weeks, indicating that the new plant has formed.
- Once the new plant has grown to about 2 inches tall, it can be transplanted to its permanent location.
Disease and Pest Management for Bidens bipinnata L.
Bidens bipinnata L. is a plant that is generally hardy against diseases and pests. However, certain environmental conditions may increase its susceptibility to diseases and pests.
Common Diseases
Bacterial leaf spot and powdery mildew are the most common diseases that affect Bidens bipinnata L. Bacterial leaf spot causes small, water-soaked, yellow-green spots on the leaves, which enlarge and become brown. Powdery mildew, on the other hand, forms a white, powdery film on the leaves, which spreads if left untreated.
Management Strategies for Bacterial Leaf Spot and Powdery Mildew
Bacterial leaf spot and powdery mildew can be prevented by ensuring that the plant is grown in well-drained soil that has good air circulation. Fertilizing and watering the plant should be done based on its needs and never in excess. Infected plant debris should be removed with a sterile tool and disposed of immediately to prevent the spread of the disease.
Treatment of mild cases of these diseases can be done through simple cultural practices, like pruning diseased leaves and decreasing humidity. However, more severe cases may require the use of chemical fungicides as prescribed by a professional.
Common Pests
Aphids and spider mites are the most common pests that infect Bidens bipinnata L. Aphids feed on the sap of the plant and cause deformation and discoloration of the leaves, while spider mites cause small yellow or white spots on the leaves, severely damaging them.
Management Strategies for Aphids and Spider Mites
Aphids and spider mites can be managed through the use of natural predators like ladybugs and lacewings. Alternatively, they can be removed manually by spraying water or insecticidal soaps on the plant. Regular observation of the plant and removing the infected plant parts is crucial for preventing their spread.
Severe infestations may require the use of chemical insecticides. It is essential to choose a product that targets the specific pest and is safe for use on Bidens bipinnata L.
By implementing these management strategies, Bidens bipinnata L. can grow healthy and free of pests and diseases, ensuring a bountiful harvest.
