Origin and Common Names
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg, also known as the ??hi?a Lehua, is a native species to the Hawaiian Islands. The plant is found in various regions of the archipelago, including Kaua'i, Moloka'i, Maui, O'ahu, and Hawai'i Island (the latter being its most prominent location). The plant's scientific name comes from the Greek words "metra" meaning "iron" and "sideros" meaning "wood" due to the plant's hard and durable wood.
The ??hi?a Lehua plant is also known by different names among the Hawaiian people, such as lehua, lehua mamo, lehua pua, pua lehua, and ??hi?a.
Uses
The plants have significant cultural, ecological, and economic value to the Hawaiian people. Ancient Hawaiians used ??hi?a Lehua for different purposes, including medicine, traditional craft-making, and ceremonies. For instance, the flower is used to make leis for special occasions such as hula and weddings, while the plant's bark was used to make kapa cloth.
The plant is also important ecologically, as it serves as a primary colonizer of bare lava, providing a habitat for various endemic species, and preventing soil erosion. This helps to maintain the health of the overall ecosystem. Additionally, the plant's nectar is a food source for honeycreepers, which are native birds to Hawaii.
General Appearance
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg is a perennial evergreen shrub or tree that can grow up to 15 meters tall. The plant has a slender trunk, measuring up to 1 meter in diameter, with a scaly bark that ranges from light to dark brown. The twigs of the plant are thin and covered with fine hairs.
The plant's leaves are ovate or oblong, and vary in size from 5 to 20 centimeters. The leaves are typically bright green and glossy, with conspicuous veins and tip. The flowers are cone-shaped, with numerous stamens, and are usually bright red but also come in shades of yellow and orange. The fruit is a small, woody, four-valved capsule that contains many small seeds.
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg is a beautiful and culturally significant plant that is emblematic of the Hawaiian Islands.
Light Requirements
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg requires full sun exposure for optimal growth. It can grow in partially shaded conditions, but this can result in reduced flowering and stunted growth of the plant. Therefore, it is recommended to provide it with at least six hours of direct sunlight per day.
Temperature Requirements
This plant is native to tropical and subtropical regions and can thrive in a temperature range between 65°F to 85°F (18°C to 29°C). It can tolerate occasional dips in temperature down to 55°F (13°C) but prolonged exposure to cold temperature below this range can damage or kill the plant. This variety of Metrosideros polymorpha is not frost-tolerant and needs protection during winter months in areas with frost.
Soil Requirements
The ideal soil for Metrosideros polymorpha Gaud. var. macrostemon Skottsberg is well-draining soil with high organic content. The plant can tolerate a wide range of soil pH, from acid to alkaline, but prefers a slightly acidic soil with a pH of 5.6–6.0. The soil should be moist but not waterlogged and must be able to retain some moisture during dry periods. The plant is not tolerant of salt spray and must be kept away from salt-laden areas.
Cultivation
The plant Metrosideros polymorpha Gaud. var. macrostemon Skottsberg, commonly known as the Hawaiian Christmas berry, is native to Hawaii and requires a tropical or subtropical climate to thrive. The plant grows best in well-drained soil with a slightly acidic pH level of 5.5 to 6.5. It needs to be planted in an area with full to partial sunlight exposure to grow optimally.
Watering Needs
The Hawaiian Christmas berry prefers to be kept moist but not wet, as it is susceptible to root rot. During the warmer months, the plant may require more frequent watering due to increased evaporation, while less watering is needed during the colder months.
Fertilization
The plant requires an adequate amount of nutrients to grow healthily and produce vibrant foliage. The best time to fertilize the plant is during the growing season, which is typically from late spring to early fall. A balanced fertilizer with an NPK (nitrogen, phosphorus, and potassium) ratio of 10-10-10 is ideal for the plant. Fertilization can be done every 4 to 6 weeks, following the instruction on the fertilizer packaging.
Pruning
Pruning of the Hawaiian Christmas berry is not required, but it can be beneficial for the plant's growth. Removing dead or damaged branches will help to promote new growth and stimulate the plant's renewal process. Pruning can be done at any time of the year but it is best to avoid pruning during the flowering season.
Propagation Methods of Metrosideros polymorpha Gaud. var. macrostemon Skottsberg
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg, commonly known as ??hi?a Lehua, is a tree native to Hawaii. It is mainly propagated through vegetative means, such as cuttings and air-layering. Here are the details about propagation methods:
Cuttings
Cuttings from young stem tips can be rooted easily in a propagating mix comprised of peat moss, perlite, and sand. The ideal stem cutting will be around 4-6 inches in length and contain a few leaves. Dip the lower end of the cutting in rooting hormone before planting it in the mix. Maintain high humidity and keep the soil moist. It takes around 2-3 months for the cutting to form roots and start growing foliage.
Air-Layering
Air-layering involves wounding the stem of the plant and inducing the formation of roots on that spot while it is still connected to the parent plant. The air-layering process is carried out by removing a 1-inch wide ring of bark from the stem of the tree. The wound is covered with a rooting hormone and covered with moist sphagnum moss held in place with plastic wrap. Roots will form in a few weeks, and the air-layer can then be cut from the parent plant and transplanted to a container filled with soil. The newly planted tree should be watered regularly for several months until it is fully established.
Disease and Pest Management for Metrosideros polymorpha Gaud. var. macrostemon Skottsberg
Metrosideros polymorpha Gaud. var. macrostemon Skottsberg, commonly known as ??hi?a Lehua, is a tree native to Hawaii and is known for its bright red flowers and cultural significance. Diseases and pests can affect the plant's growth and flower production, affecting its overall health. Here are some common diseases and pests that might affect ??hi?a Lehua and ways to manage them:
Diseases:
Rapid ??hi?a Death: This disease is caused by two types of fungi that enter the plant through wounds on the trunk or roots. The fungus can cause wood decay and can kill the tree within weeks to months. The best management method is to prevent the disease by avoiding damaging the tree's roots or trunk. Additionally, avoid transporting ??hi?a Lehua wood or soil from infected areas.
Anthracnose: This fungal disease can cause leaf spots, defoliation, and dieback. Preventative measures should be practiced, such as proper irrigation techniques (avoiding wetting the foliage), promoting good air circulation, and removing infected plant material. Fungicides may also be used as a treatment option.
Pests:
??hi?a Moth: The larval stage of this moth feeds on the plant's foliage, causing defoliation and dieback. The best way to manage this pest is through early detection and removal of infested plant material and the use of insecticides.
Mites: Mites can cause leaf discoloration, distortion, and stunted growth. Proper irrigation and fertilization practices should be used, as mites thrive in drought-stressed plants. Insecticidal soaps or oils may be used as a treatment option.
Overall, practicing preventative measures such as proper irrigation and fertilization practices, promoting good air circulation, and monitoring the plant for any signs of disease or pests can help maintain the health of Metrosideros polymorpha Gaud. var. macrostemon Skottsberg.
