Origin of Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders, also known as Kalealaha beggarticks or Kalealaha Spanish needle, is a plant that is endemic to the Hawaiian Islands. It can be found growing in dry to mesic forests, shrublands, and grasslands across the archipelago.
Common Names
Aside from Kalealaha beggarticks and Kalealaha Spanish needle, Bidens micrantha Gaud. ssp. kalealaha also goes by other common names such as Kalealaha and Lehua makanoe.
Appearance
Bidens micrantha Gaud. ssp. kalealaha is a perennial herbaceous plant that grows up to 1.5 meters in height. Its leaves are 15-20 cm long and are compound with 3-5 leaflets that have serrated edges. The flowers of the plant are yellow and relatively small, about 1 cm in diameter. They grow in clusters at the end of branches. The fruit produced is an achene, which is small and oblong-ovate in shape.
Uses
The Bidens micrantha Gaud. ssp. kalealaha has been used by native Hawaiians in traditional medicine as a treatment for various ailments such as stomach pain, fever, and headaches. The plant has also been used as a food source. The leaves can be cooked and eaten as greens while the roots were used to make a traditional Hawaiian drink called "awa. Today, the plant is mostly used in horticulture for ornamental purposes because of its bright and cheerful yellow flowers.
Light Requirements
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders requires full sun to partial shade. It can tolerate some shade but grows best in full sun, receiving at least 6 hours of direct sunlight daily.
Temperature Requirements
The plant grows well in warm temperatures, thriving in USDA Hardiness Zones 10 to 11. It cannot tolerate frost or freezing temperatures and should be protected during cold snaps.
Soil Requirements
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders prefers well-draining soils with a pH of 6.0 to 7.5. It can tolerate poor soils and soil that is slightly acidic but grows best in fertile soils rich in organic matter. It has low tolerance for soggy soils and should be planted in areas with good drainage.
Cultivation
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders, commonly referred to as Hawaiian beggar-ticks, is a low-growing plant that thrives in tropical climates. It prefers well-drained soil and can tolerate both full sun and partial shade. The plant can be propagated from seed or from stem cuttings.
When planting from seed, it's best to start indoors and then transplant the seedlings to the desired location. Sow the seeds in light, sandy soil and keep them moist until they germinate. Once the seedlings have grown to about 3 inches tall, you can transplant them into the garden.
Watering Needs
Watering needs for Hawaiian beggar-ticks will vary depending on the climate and the soil type. In general, the plant should be watered regularly but not excessively. The soil should be allowed to dry out slightly between waterings.
During periods of drought or hot weather, the plant may require more frequent watering to stay healthy. A good rule of thumb is to water deeply once or twice a week, rather than shallowly every day.
Fertilization
Hawaiian beggar-ticks typically does not require much fertilizer. A light application of a balanced fertilizer in early spring can help promote healthy growth and flowering. Alternatively, you can apply a slow-release fertilizer in early summer to provide nutrients to the plant throughout the growing season.
Be careful not to over-fertilize, as this can lead to excessive foliage growth at the expense of flower production.
Pruning
Hawaiian beggar-ticks is a relatively low-maintenance plant, and pruning is generally not required. However, if the plant becomes too leggy or starts to spread outside of its designated space, you can prune back the stems to encourage a more compact growth habit.
To do this, use a sharp pair of shears or pruners to cut back the stems by about one-third. This will help promote bushier growth and prevent the plant from becoming too thin or spindly.
Propagation of Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders, also known as Kookoolau, is a rare Hawaiian endemic plant that belongs to the family Asteraceae. It has a naturally limited range and is classified as an endangered plant as per the International Union for Conservation of Nature (IUCN) Red List due to habitat loss, invasive plants, and human impact. Propagation of this plant can contribute to its conservation and restoration efforts.
Propagation by Seeds
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders produces small black seeds that can be sown directly into a well-draining growing medium. The best time for seed sowing is in the spring or early summer. However, seed production in this species is limited, which makes it challenging to obtain enough seeds for propagation. In addition, not all seeds may germinate, and propagation by seeds can result in genetic variation among the offspring.
Propagation by Cuttings
Propagation of Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders can also be done by stem cuttings. Cuttings should be taken from mature stems in the summer when the plant is actively growing. Using a sharp, sterile knife, cut a 4-6 inch long stem with at least one node and a few leaves. Remove the bottom leaves and dip the cut end in rooting hormone. Place the cutting in a rooting medium or directly into a well-draining potting mix, mist it regularly, and keep it in a warm, partially shaded area. The cutting should root in 4-6 weeks, and it can be transplanted into a larger container or outside after the roots have established.
Propagation by Division
Bidens micrantha Gaud. ssp. kalealaha Nagata & Ganders can also be propagated by division. This method involves dividing the plant into smaller sections, each with a portion of roots and shoots. It is best done in the spring when the plant is actively growing. Using a sharp, sterile knife, divide the plant into sections, taking care not to damage the roots or shoots. Replant the sections into individual pots or directly into a well-draining growing medium, and keep them in a warm, partially shaded area. The new plants should establish roots and shoots within a few weeks and can be transplanted when they are large enough.
Disease and Pest Management for Bidens Micrantha Gaud. ssp. Kalealaha Nagata & Ganders
The Bidens Micrantha Gaud. ssp. Kalealaha Nagata & Ganders is a plant species that is prone to various diseases and pests. Below are common diseases and pests that can affect the plant and ways to manage them:
Common Diseases
1. Powdery Mildew: Powdery mildew is a common fungal disease that affects Bidens Micrantha Gaud. ssp. Kalealaha Nagata & Ganders. It appears as white or grayish powder on the leaves and can cause plant deformation. To manage powdery mildew, avoid overhead irrigation and remove any infected plant parts as soon as possible.
2. Rust: Rust is another fungal disease that can affect Bidens Micrantha Gaud. ssp. Kalealaha Nagata & Ganders. It appears as orange or yellowish spots on leaves and can lead to premature leaf drop. To manage rust, use fungicide sprays and ensure proper plant spacing to increase air circulation.
3. Leaf Spot: Leaf spot is a bacterial or fungal disease that appears as brown or black spots on leaves and stems. It can be managed by removing and destroying infected plant parts and applying fungicide sprays.
Common Pests
1. Aphids: Aphids are small, soft-bodied insects that feed on plant sap and can cause yellowing and curling of leaves. To manage aphids, use insecticidal soap or spray with a strong stream of water to dislodge them.
2. Spider Mites: Spider mites are tiny pests that feed on plant juice and can cause yellowing and stippling of leaves. To manage spider mites, use insecticidal soap or neem oil and ensure proper plant hydration to prevent infestations.
3. Slugs and Snails: Slugs and snails can chew on leaves and leave large holes on plant parts. To manage them, use slug bait and remove any debris or hiding places around the plants to deter them.
Regular monitoring and prompt action are essential to managing diseases and pests in Bidens Micrantha Gaud. ssp. Kalealaha Nagata & Ganders successfully.
