Description:
Metrosideros collina ssp. polymorpha, commonly known as the "??hi?a Lehua" in Hawaii, is a small to medium-sized tree that belongs to the myrtle family. It is a native plant that can be found in the Hawaiian Islands, ranging from sea level up to an elevation of 2,400 meters (7,900 feet). This species displays a remarkable range in leaf and flower shape, hence the subspecies epithet "polymorpha" which means "many forms".
Appearance:
The beautiful, dark green leaves of the ??hi?a Lehua are oval in shape and measure around 15 centimeters (6 inches) in length, with a prominent midrib and a glossy, smooth surface. The bark of this tree is grey-colored, with a rough texture. The flowers of the ??hi?a Lehua feature brilliant red, pink, or yellow stamens, with petals ranging from yellow to orange or red, that create a stunning, showy display.
Uses:
The ??hi?a Lehua is a revered plant in Hawaiian culture, folklore, and mythology. It has many traditional uses, such as making leis from the flowers and leaves or using the hard, dense wood for carving and making tools. Additionally, the plant has medicinal properties – the leaves, bark, and flowers can be used to treat various ailments. However, it must be noted that the plant is endangered due to the spread of a deadly fungus called rapid ??hi?a death, which makes the conservation of this species particularly important.
In summary, Metrosideros collina ssp. polymorpha, also known as the ??hi?a Lehua, is a unique and beautiful tree that is native to the Hawaiian Islands. It displays a wide range of leaf and flower shapes, has a grey bark with a rough texture, and produces beautiful flowers of various colors. It is a significant plant in Hawaiian culture, used for traditional purposes like leis and tool-making, as well as medicinal applications. However, the species is currently endangered, and measures must be taken to protect and preserve it.Light Requirements
Metrosideros collina ssp. polymorpha typically prefers full sun to partial shade for optimum growth. This species tolerates a range of lighting conditions but requires a minimum of six hours of daily sunlight for healthy growth.
Temperature requirements
This species performs well in humid subtropics and is adaptable to a range of temperatures. However, cooler temperatures and moist environments promote healthier growth. Metrosideros collina ssp. polymorpha can endure temperature fluctuations but cannot withstand extreme highs or lows. The ideal temperature range for healthy growth is between 20°C and 30°C (68°F-86°F).
Soil Requirements
Metrosideros collina ssp. polymorpha is a versatile plant that can grow in a wide range of soils. It thrives best in well-drained soils that are rich in organic matter. The soil pH should be slightly acidic to neutral, ranging from 5.6 to 7.5. This species prefers soils with good moisture retention capacity, but it should not be waterlogged.
Cultivation Methods
Metrosideros collina (J.R. & G. Forst.) Gray ssp. polymorpha (Gaud.) Rock, commonly known as the Hawaiian Christmas Berry, requires full sun to partial shade to thrive. It grows best in well-draining soils with a pH range of 5.6 - 6.5. It can be propagated through seed or cuttings. Seeds should be collected when the berry turns yellow-orange, and then let dry for a few days. Cuttings are best taken from semi-hardwood in the spring. It is a fast-growing plant that can reach up to 30 feet tall, but it can also be grown as a bonsai if pruned regularly.Watering Needs
Metrosideros collina requires regular watering, especially during dry seasons. The soil should be kept evenly moist, but avoid waterlogging the soil as it can cause root rot. Watering frequency should be adjusted according to the plant's stage of growth. Newly planted or young plants require more water, while mature plants can tolerate droughts better.Fertilization
Fertilizers should be applied in small amounts to Metrosideros collina twice a year - in the spring and fall. Use a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium, such as 10-10-10 or 14-14-14. Avoid over-fertilization as it can lead to the buildup of salts that can damage the roots.Pruning
Pruning should be done regularly to maintain the desired size, shape, and health of the plant. Dead, diseased, or damaged branches should be removed as soon as possible to prevent the spread of infection. New growth should be pinched back regularly to promote branching and fullness. If growing as a tree, the lower branches can be removed to create a taller trunk. When grown as a bonsai, the plant should be wired and pruned to create the desired shape.Propagation of Metrosideros collina ssp. polymorpha
Metrosideros collina ssp. polymorpha, also known as the Hawaiian Christmas berry, is a small tree native to Hawaii. It is known for its bright red berries that appear during the Christmas season. Propagation of this plant can be done through several methods:
Seed propagation
Seeds of Metrosideros collina ssp. polymorpha can be collected from the ripe berries during the winter season. The seeds should be sown immediately in a well-draining potting mix and kept in a warm and humid location. Germination of seeds can take around 4 to 6 weeks.
Cuttings propagation
Cuttings of Metrosideros collina ssp. polymorpha can be taken from semi-hardwood shoots during early summer or spring. The cuttings should be around 4 to 6 inches in length and have at least 3 nodes. The leaves on the lower half of the cutting should be removed, and rooting hormone can be applied to the base of the cutting before planting it in a well-draining rooting medium. Cuttings should be kept in a warm and humid location until new growth appears.
Air layering propagation
Air layering can be done on mature branches of Metrosideros collina ssp. polymorpha during the growing season. A 6 to 8 inch section of the stem should be selected and a ring of bark should be removed from around the branch. Hormone rooting powder can be applied to the exposed area, which is then covered with moist sphagnum moss and secured with plastic. Once roots have developed, the branch can be cut below the rooted area and planted in a well-draining potting mix.
Overall, Metrosideros collina ssp. polymorpha can be propagated through seed, cuttings, or air layering methods. Propagation can be done all year round, but the best time is during the growing season.
Disease Management
The most common diseases that affect Metrosideros collina ssp. polymorpha include:
- Anthracnose: This is a fungal disease that causes brown or black spots on the leaves and stems of the plant. It can be managed by removing infected plant parts and fungicidal sprays.
- Leaf Spot: This disease causes brown or black spots on the leaves of the plant. It can be managed by removing infected plant parts and fungicidal sprays.
- Sooty Mold: This is a fungal disease that can affect the plant leaves, stems, and flowers, turning them black and sooty. It can be managed by removing infected plant parts and spraying the plant with a fungicide.
- Phytophthora Root Rot: This fungal disease can cause the roots of the plant to become soft and mushy, eventually leading to plant death. It can be managed by improving soil drainage and avoiding overwatering.
Pest Management
Common pests that might affect Metrosideros collina ssp. polymorpha include:
- Aphids: These insects suck sap from the plant leaves, causing them to curl and turn yellow. It can be managed by spraying the plant with insecticidal soap or neem oil.
- Mites: These tiny insects can cause webbing on the leaves and stunt plant growth. They can be managed by spraying the plant with insecticidal soap or neem oil.
- Mealybugs: These insects can cause a white, waxy substance to appear on the plant leaves and stems. They can be managed by removing infected plant parts and spraying the plant with insecticidal soap or neem oil.
- Scale Insects: These insects can cause yellowing of leaves and stunted plant growth. They can be managed by removing infected plant parts and spraying the plant with insecticidal soap or neem oil.
