Origin
Metrosideros polymorpha Gaud. var. polymorpha, commonly known as the ??hi?a Lehua, is a species of flowering plant in the myrtle family, Myrtaceae. This plant is endemic to the Hawaiian Islands and can be found in various locations such as wet forests, bogs, high elevation shrublands, and dry forests. The plant has been introduced to other parts of the world such as Fiji, French Polynesia, and New Zealand. The plant is considered sacred by the Hawaiian people.
Common Names
??hi?a Lehua is the Hawaiian common name for Metrosideros polymorpha while in New Zealand it is called Southern Rata. In Fiji and Samoa, it is known as M?tava and Falu respectively. The plant is also called Lehua, ‘?hi‘a ,and Hawaiian Ironwood. These names allude to the toughness of the wood and the brilliant red flowers.
Uses
The plant plays a crucial role in the Hawaiian ecosystem. It acts as a pioneer species that colonizes lava flows and creates the foundation for other plant species to grow. In Hawaiian culture, the plant has spiritual significance and is a symbol of love and devotion. It is used in the production of various materials such as wood fuel, tool handles, and Hawaiian hula sticks. In addition, its nectar is used to make honey in Hawaii. The flowers are also used in lei making and in traditional medicine to soothe sore throats and upper respiratory infections.
General Appearance
Metrosideros Polymorpha Gaud. var. Polymorpha is a small to medium-sized tree that can grow up to 25 meters tall. The plant has a dense crown and a lush, dark green foliage made up of simple, leathery leaves. The bark is dark reddish-brown but can vary from a light gray to almost black. The flowers are bright red and tubular-shaped, growing in clusters at the tips of the branches. The flowers bloom throughout the year but bloom heaviest in the summer and fall. The plant is highly adaptable, and different varieties can be seen growing in different environments such as bogs, rainforests, and even on the drier slopes.
Overall, Metrosideros polymorpha Gaud. var. polymorpha is a significant and beautiful plant with cultural, ecological, and economic importance.Light Requirements:
Metrosideros polymorpha Gaud. var. polymorpha, commonly known as the ??hi?a lehua, requires a significant amount of sunlight exposure to grow optimally. They grow well in full sun or partial shade not exceeding 70%. Lack of adequate light may lead to stunted growth, reduced flower production, and even death.
Temperature Requirements:
The typical temperature range for Metrosideros polymorpha Gaud. var. polymorpha is between 16°C and 27°C. They thrive well in warm tropical and subtropical climates with high humidity. Frost and cold temperatures below 7°C can severely damage their leaves and cause the death of the whole plant.
Soil Requirements:
Metrosideros polymorpha Gaud. var. polymorpha grows optimally in well-drained acidic soil with a pH range of 4.5 to 6.5. They prefer soil that is rich in organic matter and contains high amounts of nutrients with good moisture retention. They can tolerate a variety of soils, including loam, clay, and sand, as long as they are well-drained.
Cultivation
Metrosideros polymorpha Gaud. var. polymorpha or ??hi?a lehua is a native plant of Hawaii, and it can be grown in tropical and subtropical regions. It is a hardy plant that can withstand strong winds, salt spray, and drought, making it an ideal choice for beachside gardens. This plant grows well in well-draining soil that is slightly acidic (pH 5.5 to 6.5) and requires full sunlight to partial shade. It is best to plant ??hi?a lehua during the rainy season, and it is essential to monitor the plant's growth for the first few weeks after transplanting.
Watering needs
The ??hi?a lehua plant requires consistent watering, and the soil should be moist but not soggy. The plant's water needs may vary depending on the soil, humidity, and temperature, so frequent monitoring of the soil moisture level is recommended. During the rainy season, irrigation may need to be reduced, while during the dry season, the plant may require more frequent watering. It is essential to avoid overwatering the plant, which can result in root rot or other fungal diseases.
Fertilization
Metrosideros polymorpha Gaud. var. polymorpha does not require frequent fertilization as it can obtain nutrients from the soil. However, fertilizing the plant during the growing season can promote healthier growth. It is recommended to use a balanced fertilizer with an N-P-K ratio of 10-10-10. Fertilizing should be done every two to three months with a light application to avoid overfertilization, which can damage the plant and promote excessive growth.
Pruning
Pruning Metrosideros polymorpha Gaud. var. polymorpha is not required, but occasional trimming can help maintain the plant's shape and promote blooming. It is recommended to prune the plant after it has bloomed, and any dead or diseased branches should be removed. It is essential to use sharp, clean pruning tools to avoid damaging the plant. The best time to prune the plant is during the early spring or late winter, before it begins to bloom.
Propagation of Metrosideros polymorpha Gaud. var. polymorpha
Metrosideros polymorpha Gaud. var. polymorpha, commonly known as ??hi?a Lehua, is a native Hawaiian plant species that belongs to the myrtle family. This evergreen plant species is well known for its diverse forms and is regarded as one of the most important plant species in the Hawaiian Islands. The plant has a variety of uses, including the production of ornamental plants, landscape hedges, and for cultural and medicinal purposes.
Propagation Methods
There are several methods of propagating Metrosideros polymorpha Gaud. var. polymorpha, including:
Seed Propagation
Seeds of Metrosideros polymorpha Gaud. var. polymorpha can be collected from mature fruits and used for propagation. The seeds are then prepared for germination by removing the fleshy outer layer and drying them, after which they can be sown into seeding trays filled with coarse sand or a well-drained potting mix. The seeds should be sprinkled lightly on top of the medium and covered lightly with soil. The trays should then be placed in a warm, well-lit location until germination occurs.
Cuttings Propagation
The stem cuttings of Metrosideros polymorpha Gaud. var. polymorpha can be taken from a mature plant and grown into a new plant. The cuttings should be taken in the early morning or late afternoon and should have at least two pairs of leaves. The cuttings should then be immediately dipped in a rooting hormone and inserted into a well-drained rooting medium such as a perlite mixture. The cuttings should then be kept under high humidity and good lighting until roots develop.
Air Layering
Air layering is another propagation method that can be used for Metrosideros polymorpha Gaud. var. polymorpha. This method involves selecting a branch from the parent plant, making a wound in the bark, and then covering the wounded area with a moist medium such as sphagnum moss. Once the roots have developed, the branch can be removed from the parent plant and planted in a pot or directly in the ground.
It is important to note that Metrosideros polymorpha Gaud. var. polymorpha is a slow-growing plant and may take several years to reach maturity.
Disease and Pest Management for Metrosideros polymorpha Gaud. var. polymorpha
Metrosideros polymorpha Gaud. var. polymorpha, commonly known as ??hi?a Lehua or Hawaiian ??hi?a, is a species of flowering evergreen tree endemic to Hawaii. It is important to manage diseases and pests that might affect the plant to promote its growth and development.
Common Diseases
One common disease that affects Metrosideros polymorpha is Rapid ??hi?a Death (ROD), which is caused by two distinct species of fungi – Ceratocystis fimbriata and Ceratocystis lukuohia. The fungi infect the trees through open wounds or natural openings in the bark and can cause wilting, yellowing, and death of the tree. Another common disease that affects the plant is Myrtle rust, caused by Austropuccinia psidii. It is a fungal disease that causes yellowing and falling of leaves, stunting of plants, and ultimately death.
Disease Management
ROD can be managed by avoiding pruning or wounding the tree, practicing good sanitation, and avoiding movement of infected plant material. Early detection and removal of infected trees can prevent further spread. Myrtle rust can be managed by removing and destroying infected leaves, improving air circulation around the trees, and applying fungicides.
Common Pests
The most common pests that affect Metrosideros polymorpha are scale insects, leafhoppers, and thrips. Scale insects such as Pulvinaria urbicola and Unaspis citri are sap-sucking pests that can cause yellowing of leaves, stunted plant growth, and premature leaf drop. Leafhoppers cause damage to the plant by piercing the leaves and sucking the sap, leading to yellowing, wilting, and reduced growth. Thrips also cause damage by feeding on leaves and flowers, leading to a deformed and distorted appearance.
Pest Management
Pest management can be achieved through regular monitoring of the trees for signs of infestation, removal of infected plant parts or trees, and application of insecticides or fungicides. Insecticides such as neem oil or horticultural oils can be used to control scale insects and leafhoppers. Thrips can be managed by pruning off affected plant parts or by using insecticidal soap or neem oil.
Overall, management of diseases and pests in Metrosideros polymorpha Gaud. var. polymorpha is essential to maintain healthy trees and promote their growth and development. Early detection and management can prevent further spread and save the affected trees.
