Overview
Bidens hawaiensis Gray is a flowering plant that belongs to the Asteraceae family. It is an endemic species found only in the Hawaiian Islands. The plant is commonly known as A?e or K?k?k? in the Hawaiian language.
Appearance
Bidens hawaiensis Gray is a small, branched shrub that grows up to 3 feet tall. It has bright green leaves that are oblong or elliptic in shape and grow up to 5 inches long. The plant produces yellow daisy-like flowers that are about 1 inch in diameter with a central yellow disk and 10-15 yellow petals that resemble rays. The plant blooms from June to November.
Uses
Bidens hawaiensis Gray has several uses in Hawaiian culture. The leaves were used to make lei and the bark was used for dyeing. The plant also has medicinal properties and was used to treat skin rashes and wounds by applying the sap or crushed leaves. The plant is also an important source of nectar and pollen for bees and other pollinators.
Today, Bidens hawaiensis Gray is grown as an ornamental plant in gardens and landscapes. It is attractive to butterflies and other pollinators, making it a good addition to a pollinator garden. The plant prefers well-drained soils and full sun to grow.
Light Requirements
Bidens hawaiensis Gray requires a lot of sunlight to grow. It needs to be placed in an area where it will receive full sun exposure for at least six hours every day. A lack of sunlight will slow down its growth, and the plant may not produce flowers if it doesn't get enough sunshine.
Temperature Requirements
The plant is native to Hawaii's tropical climate and thrives in warm temperatures ranging between 75°F to 85°F. The minimum temperature for the plant is 60°F, and exposure to cold temperatures may cause the plant's growth to stunt. The plant can withstand high humidity in its environment, which is common in tropical regions.
Soil Requirements
Bidens hawaiensis Gray prefers moist, well-draining soil to grow. The ideal pH range for the plant's growth is between 5.5 to 7.5. It requires rich soil with organic matter, and soil fertility can be improved by adding compost. The plant can tolerate salt spray and can grow well in coastal dunes.
Watering Requirements
The plant requires regular watering to keep the soil moist, especially during the dry season. However, the soil should not be waterlogged as it may lead to root rot. It is best to water the plant in the morning to allow excess water to evaporate before night, as the plant is susceptible to fungal diseases.
Cultivation Methods
Bidens hawaiensis Gray is a perennial plant that grows well in warm and humid climates. The plant prefers a well-drained soil that is rich in organic matter. It can grow either in full sun or partial shade. This plant does well in USDA Zones 10-11, preferring temperatures between 70 to 80 degrees Fahrenheit. It can be propagated through stem cuttings or by seeds.
Watering Needs
Bidens hawaiensis Gray requires frequent watering to thrive and should be watered regularly. The soil should not be allowed to dry out completely, as this can lead to stunted growth and reduced flowering.
Fertilization
To achieve optimal growth and health, Bidens hawaiensis Gray should be fertilized during the growing season, ideally with a balanced fertilizer. The plant responds well to slow-release fertilizers but can also benefit from regular applications of compost or well-rotted manure.
Pruning
Pruning Bidens hawaiensis Gray helps to keep the plant looking attractive and encourages the production of more blooms. Deadheading, the process of removing dead flowers, can help to prolong the flowering period and can be carried out by pinching or cutting back spent blooms. The plant can also be pruned back in the autumn to promote bushier growth the following year.
Propagation of Bidens Hawaiensis Gray
Bidens hawaiensis Gray, also known as Ko'oko'olau, is a Hawaiian endemic plant species found on the islands of Kauai, Oahu, Maui, Molokai, and Hawaii. The plant belongs to the Asteraceae family and is a popular choice for landscaping due to its attractive yellow flowers.
Propagation by Seeds
The primary propagation method for Bidens hawaiensis Gray is by seeds. The plant produces seeds in abundance but has a low germination rate if left untreated. To increase the germination rate of Bidens hawaiensis Gray seeds, scarification is necessary. Scarification is the process of breaking, scratching, or softening the seed coat to allow for the entry of water and air.
After scarification, the seeds should be soaked in water for 24 hours to promote hydration. Sow the seeds in trays or pots filled with a well-draining soil mixture. Cover the seeds with a light layer of soil and maintain soil moisture by misting daily. The seeds will germinate within two to four weeks.
Propagation by Cuttings
Bidens hawaiensis Gray can also be propagated by stem cuttings. Take cuttings from softwood stems during the growing season in the spring or summer. Cut a 4 to a 6-inch section of stem below a node and remove the lower leaves, leaving only two or three leaves on the top. Dip the cut end in rooting hormone and plant in a well-draining soil mix.
Place the cutting in a warm, humid location with bright, indirect light. Keep the soil moist by misting daily. The cutting will develop roots in two to four weeks and can be transplanted to a larger pot or outdoors once established.
Propagation by Division
Bidens hawaiensis Gray can also be propagated by division. This method involves dividing the parent plant into smaller sections, each with its own root system. Division is typically done in the spring or fall when the plant is dormant.
Start by digging up the entire plant, taking care not to damage the root system. Gently separate the roots and stems into smaller sections using a sharp knife or garden shears. Each section should have several stems and a healthy root system. Replant the divided sections in a well-draining soil mixture and water thoroughly.
Propagation by seeds, cuttings, and division are reliable methods for expanding your collection of Bidens hawaiensis Gray plants. By following these simple techniques, you can propagate the plant and enjoy its beautiful flowers in your garden or landscape.
Disease and Pest Management for Bidens hawaiensis Gray
Bidens hawaiensis Gray, commonly known as Hawai'i beggarticks, is a perennial plant found in moist areas, including wetlands, marshes, and riverbanks. Like many plants, it is susceptible to diseases and pests that can seriously affect its growth and overall health. Here are some common diseases and pests that affect Bidens hawaiensis Gray, along with suggestions for how to manage them.
Diseases
Leaf Spot: Leaf spot is a fungal disease that presents as brown or black spots on the leaves of the plant. It can be caused by a variety of fungi and can be exacerbated by humid conditions. To manage leaf spot, remove infected leaves and dispose of them away from the plant. Additionally, ensure good air circulation and avoid overhead watering. Fungicides may also be effective.
Rust: Rust is a fungal disease that appears as yellow or brown spots on the leaves and stems of the plant. Over time, these spots may become raised and develop a rust-like appearance. To manage rust, remove infected plant material and dispose of it away from the plant. Ensure good air circulation and avoid overhead watering. Fungicides may also be effective.
Pests
Caterpillars: Caterpillars are the larval stage of moths and butterflies and can cause significant damage to Bidens hawaiensis Gray by feeding on the leaves. To manage caterpillar infestations, handpick and remove the larvae as soon as they are observed. Additionally, biological control methods such as spraying with Bacillus thuringiensis may be effective.
Whiteflies: Whiteflies are small, winged insects that feed on the sap of the plant and can cause stunted growth and a yellowing of the leaves. To manage whiteflies, introduce natural predators such as ladybugs or lacewings. Additionally, spraying the plant with a soap and water solution may help to deter infestations.
By practicing good cultural and management practices, Bidens hawaiensis Gray can be protected from diseases and pests that may impact its growth and overall health.
