Overview
Metrosideros polymorpha Gaud. var. incana, also known as ??hi?a lehua in Hawaiian, is a plant species native to Hawaii that belongs to the family Myrtaceae. This species is known for its striking red flowers and is a popular cultural symbol in Hawaiian folklore and mythology.
Description
The ??hi?a lehua is a small to medium-sized evergreen tree that can reach up to 25 feet in height. It has a broad and dense crown with a smooth, grayish-brown bark. The leaves are dark green, glossy, and elliptic in shape, measuring up to 12 cm in length. The most outstanding feature of this plant is its vibrant red flowers, which bloom in clusters at the tips of the branches and the base of the leaves. These flowers are composed of numerous stamens and are surrounded by four to five petals, which give them a spherical or cylindrical shape.
Origin
The ??hi?a lehua is endemic to the Hawaiian Islands and can be found on all major islands. It thrives in a variety of habitats, including wet and dry forests, subalpine shrublands, and lava fields. This species is considered a pioneer species, meaning that it is one of the first plants to establish itself on new lava flows.
Common Names
The ??hi?a lehua is known under a variety of common names in Hawaii, including lehua, ohia, and pua lehua. It is also commonly referred to as the Hawaiian paperbark tree due to its distinctive peeling bark.
Uses
The ??hi?a lehua has a significant cultural importance in Hawaiian tradition and is considered a sacred plant. It is often used in hula performances and lei making, as well as for medicinal purposes. The flowers and bark of the tree have been used to treat a variety of illnesses, including asthma, sore throat, and infections. The wood of the ??hi?a lehua is hard and durable, making it useful for construction and the production of tools and furniture.
Growth Conditions of Metrosideros polymorpha var. incana
Metrosideros polymorpha var. incana is a rare variety of the well-known native Hawaiian plant species commonly known as ??hi?a lehua. It is a woody evergreen tree that can grow up to 15 meters tall with a trunk that can be one or several meters in diameter. The following are the typical growth conditions required for this plant to thrive:
Light
Metrosideros polymorpha var. incana requires abundant sunlight to thrive. It prefers full sun and can tolerate partial shade when young. In general, the more sunlight the plant receives, the better it will grow. Therefore, it is advisable to plant it in an open area rather than under a dense tree canopy.
Temperature
M. polymorpha var. incana grows well in a subtropical climate with high humidity and mild temperatures. The plant is adapted to a wide range of temperatures, with a preference for moderate heat between 18 and 28°C. However, it can also grow in cooler temperatures of 10 to 15°C. This plant variety is frost-tolerant and can survive occasional freezing temperatures.
Soil
The plant grows well in well-draining soils that are rich in organic matter. In its natural habitat, it is typically found in volcanic soils or soils derived from volcanic rocks. Therefore, it prefers slightly acidic soils with a pH range between 5.5 and 6.5. The species can tolerate a variety of soil types, from sand to clay, as long as they are well-draining.
Cultivation methods for Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg
M. polymorpha is commonly known as 'ohia lehua,' a plant endemic to Hawaii. It prefers to grow in well-drained soil on the upper slopes of volcanoes. Before planting, work the soil deeply and amend with organic matter to improve drainage and fertility. The plant requires full sun and prefers cooler temperatures for maximum growth.
Plant M. polymorpha 12 to 15 feet apart, allowing plenty of room for the roots to spread. It is recommended to plant in early spring or fall when temperatures are cooler. Provide the young plant with some protection from strong winds and direct sunlight to prevent transplant shock.
Watering needs for Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg
Water M. polymorpha regularly at least once a week during the growing season, and make sure the soil stays evenly moist, but not waterlogged. It can tolerate some drought, but it's best to water deeply when the soil feels dry to the touch. Reduce watering in winter to avoid root rot, which can kill the plant.
Fertilization for Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg
Use organic fertilizers such as bone meal, blood meal or fish emulsion every six weeks during the growing season to promote healthy growth, blooming and fruiting of M. polymorpha. Avoid using high-nitrogen fertilizers as they can damage the plant.
Pruning of Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg
M. polymorpha does not require routine pruning, but it may need shaping or reducing if it outgrows its designated space. Prune after blooming by cutting back long, errant branches and removing any damaged or diseased wood. Deadheading spent flowers regularly will promote new growth and blooming of fresh flowers.
Propagation of Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg
Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg, also known as the ‘?hi‘a Lehua, is endemic to Hawaii and is a popular plant grown for its beautiful flowers and foliage. This plant can be propagated by several methods that include:
Seed Propagation
The plant can be propagated through seed, which is an easy and simple method. Collect mature seeds from the plant, clean and dry them before sowing them in a well-draining soil mixture. Place the pots in bright, indirect light, and maintain a constant moisture level until the germination of seeds occurs.
Cuttings Propagation
The plant can also be propagated through cuttings. Collect cuttings at least 4 inches long from the tip of a healthy branch and remove the leaves from the lower half of the cutting to expose the stem. Dip the cuttings in rooting hormone powder and plant them in a moist, well-draining soil mixture. Place the plant in a bright, indirect light, and maintain a constant moisture level until the roots develop.
Air Layering
Air layering is another propagation method that is effective for Metrosideros polymorpha. In this method, select a healthy stem and remove a section of the bark(1 inch wide) from the plant. Apply rooting hormone to the exposed area. Wrap damp sphagnum moss around the exposed area and wrap it with plastic wrap. Within a few months, the roots will develop within the moss. Snip the rooted section from the mother plant and plant it into a well-draining soil mixture.
Propagation of Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg can be done easily through the above-mentioned methods. Ensure that you take the necessary precautions and maintain ideal conditions to ensure successful propagation.
Disease Management
Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg is susceptible to a few common diseases such as:
- Anthracnose: This fungal disease causes brown spots on the leaves, which may eventually cause defoliation. It can be managed by removing and disposing of infected leaves, improving air circulation, and applying fungicide.
- Powdery Mildew: This fungal disease causes a white powdery substance to form on the leaves, which can lead to curling and distortion. It can be managed by removing infected plant parts, improving air circulation, and applying fungicide.
- Phytophthora Root Rot: This fungal disease causes root rot and can cause plants to wilt and die. It can be prevented by ensuring proper drainage and watering practices, planting in well-draining soil, and avoiding overwatering.
Pest Management
Some common pests that may affect Metrosideros polymorpha Gaud. var. incana (Levl.) Skottsberg include:
- Aphids: These small insects feed on the sap of the plant and can cause stunted growth and distorted leaves. They can be managed by removing them with a strong stream of water or applying insecticidal soap.
- Spider Mites: These tiny pests can be difficult to see but can cause yellowing and webbing on the leaves. They can be managed by washing the leaves with water, applying insecticidal soap, or using predatory mites.
- Snails and Slugs: These common pests can eat large holes in the leaves and can be managed by handpicking them or using slug bait.
Regular monitoring of the plant and prompt action can often prevent serious damage from diseases and pests. It is important to also follow good cultural practices like keeping the plant healthy and well-maintained to help prevent infestations.
