Origin of Metrosideros polymorpha Gaud. ssp. glabrifolia
Metrosideros polymorpha Gaud. ssp. glabrifolia, also known as ?hi‘a lehua, is a species of flowering plant in the myrtle family, Myrtaceae. It is native to the Hawaiian Islands and can be found growing from sea level up to an elevation of 8,000 feet on all of the main islands except Ni'ihau and Kaho'olawe.
Common Names
The common name, ?hi‘a lehua, refers to both the plant and its strikingly beautiful flowers, which are often used for ornamental purposes. Other common names for this plant include Hawai‘i lehua, pua lehua, lehua, ‘?hi‘a, and mountain apple.
Uses
?hi‘a lehua is an important plant in Hawaiian culture and mythology. The flower is one of the most popularly used flowers in cultural ceremonies and is often given as a gift to show love and respect. The plant has many uses in traditional Hawaiian medicine and is used to treat various ailments. The wood is also used to make tools, weapons, and other items.
General Appearance
?hi‘a lehua is a medium-sized evergreen tree and can reach heights of up to 100 feet. The tree has smooth, greyish-brown bark, and its leaves are leathery, dark green, and shiny. The flowers are bright red or pink and grow in clusters at the end of the branches. The fruit is a woody capsule that contains many small seeds.?hi‘a lehua is a beautiful and important plant in Hawaiian culture, and its unique appearance and cultural significance make it a popular ornamental plant in many gardens around the world.
Light Requirements
Metrosideros polymorpha Gaud. ssp. glabrifolia prefers full sun exposure for optimal growth. The plant can tolerate partial shade, but it may cause reduced flower production and growth in the long term. Therefore, it is essential to ensure that the plant receives adequate sunlight to maintain its healthy growth.
Temperature Requirements
The plant grows best in warm regions with temperatures ranging from 25-28 degrees Celsius. It can tolerate temperatures as low as 10 degrees Celsius and as high as 35 degrees Celsius. However, it may not grow and produce flowers optimally under these extreme conditions. It may also require some protection from strong winds, as it is prone to wind damage.
Soil Requirements
Metrosideros polymorpha Gaud. ssp. glabrifolia thrives in well-drained, fertile, and slightly acidic soils with pH levels ranging from 5.5 to 6.0. It can tolerate different soil types, including loamy, sandy, and volcanic soils. However, it may have difficulties growing in poorly drained soils or stagnant water conditions. Therefore, it is important to ensure the plant does not sit in waterlogged soil.
Cultivation Methods
Metrosideros polymorpha Gaud. ssp. glabrifolia is a relatively easy plant to cultivate as long as you provide the right growing conditions. This plant thrives in full sun to partial shade and needs a well-draining soil mix with a slightly acidic pH level. The ideal temperature range for growth is between 60-80°F. This plant is not particularly frost tolerant, so it's best to keep it indoors or protect it during the winter months.
The plant can be grown from seeds, cuttings, or by division. Seeds can be planted in trays filled with a well-draining soil mix and kept in a warm, brightly lit area until they germinate. Cuttings can be taken from healthy plants and rooted in a well-draining mix. Division involves separating the plant into smaller sections and repotting them in fresh soil mix.
Watering Needs
Metrosideros polymorpha Gaud. ssp. glabrifolia prefers regular watering, especially during the growing season. The soil should be kept moist, but not waterlogged. It's important to not let the soil dry out completely between waterings, as this can cause stress to the plant and lead to wilting or leaf drop. During the winter months, reduce watering frequency, as the plant's growth slows down and it needs less water.
Fertilization
Regular fertilization is key to keeping Metrosideros polymorpha Gaud. ssp. glabrifolia healthy and thriving. A balanced, water-soluble fertilizer can be applied every 4-6 weeks during the growing season. Be sure to follow the manufacturer's instructions carefully, as over-fertilizing can lead to nutrient burn and damage to the plant's roots.
Pruning
Metrosideros polymorpha Gaud. ssp. glabrifolia benefits from occasional pruning to maintain its shape and encourage bushier growth. Prune back any dead, damaged, or diseased branches as soon as you notice them. You can also pinch back new growth to encourage side branching. Avoid heavy pruning, as this can cause stress to the plant and lead to reduced blooming.
Propagation of Metrosideros polymorpha Gaud. ssp. glabrifolia (Heller) Skottsberg
Metrosideros polymorpha Gaud. ssp. glabrifolia (Heller) Skottsberg, also known as the smooth-leaved '?hi'a, is a native Hawaiian plant that can thrive in a variety of ecological settings. It is typically propagated through seeds and cuttings, and several methods of propagation have been found to be successful.
Propagation through Seed Germination
The seeds of Metrosideros polymorpha Gaud. ssp. glabrifolia (Heller) Skottsberg can be collected from mature fruits that have fallen from the tree. The fruits should be cleaned, and the seeds should be removed and dried in a cool, shaded place. Once dried, the seeds can be sowed in a seed tray filled with sterile, moist soil.
The seed tray should be placed in a bright, humid place, and the soil should be kept consistently moist. Germination typically occurs within 3-6 weeks, and the seedlings can be transplanted to individual pots or directly to the ground once they have developed at least two sets of true leaves.
Propagation through Stem Cuttings
Another method of propagating Metrosideros polymorpha Gaud. ssp. glabrifolia (Heller) Skottsberg is through stem cuttings. Cuttings should be taken from mature, healthy plants during the spring or summer months. The cuttings should be approximately 6 inches long and should include at least two nodes.
The bottom of the cutting should be dipped in rooting hormone, and then it should be planted in a pot filled with moist, well-draining soil. The pot should be placed in a bright, humid location and the soil should be kept consistently moist. Roots should begin to form within 4-6 weeks, at which point the cutting can be transplanted to an individual pot or directly to the ground.
Disease and Pest Management for Metrosideros Polymorpha Gaud. ssp. Glabrifolia (Heller) Skottsberg
Metrosideros polymorpha Gaud. ssp. glabrifolia (Heller) Skottsberg, commonly known as the ‘?hi‘a lehua tree, is a native Hawaiian plant species that is vulnerable to several diseases and pests. Here are some common diseases and pests that can affect the plant and ways to manage them.
Diseases
Rapid ‘?hi‘a Death (ROD)
The most significant disease affecting Metrosideros polymorpha ssp. glabrifolia is Rapid ‘?hi‘a Death (ROD), caused by the fungal pathogens Ceratocystis lukuohia and Ceratocystis huliohia. The disease leads to wilting and death and has played a significant role in the decline of ‘?hi‘a forests in Hawaii. There is no cure for ROD, and the best management strategy is to prevent the spread of the disease. This involves not transporting wood or soil from infected areas, sanitizing equipment, and avoiding creating wounds on healthy trees, which can serve as entry points for the fungus.
Lichen Strangling
Lichen Strangling is a disease that occurs when a type of lichen grows around the tree branches and cuts off circulation. If not managed, it can lead to the death of the tree. Pruning affected branches and maintaining tree health by giving the tree optimal growing conditions is the best way to manage Lichen Strangling.
Pests
Lehua Mite
The ‘?hi‘a tree is prone to infestations by the lehua mite (Eriophyes euphorbiae). These mites feed on the leaves of the tree, causing red galls on the leaves. The best way to manage the lehua mite is by using pesticides or beneficial predators such as the lady beetle.
Tea Scale Insects
Tea scale insects are tiny insects that feed on the leaves of the ‘?hi‘a tree, causing leaves to yellow and die. They produce a waxy coating that makes them difficult to control with pesticides, and the best way to manage them is by using sticky traps, pruning heavily infested branches or using beneficial predators such as the lady beetle.
Mistletoes
Mistletoes are parasites that attack the ‘?hi‘a tree, and if left untreated, they lead to severe damage or death of the tree. The best way to manage mistletoes is by pruning affected branches or removing them entirely.
The ‘?hi‘a lehua tree is iconic to the Hawaiian landscape, and its conservation is crucial. Therefore, detecting and managing diseases and pests that attack the tree is necessary for the tree’s survival. Regular monitoring of the tree and giving it optimal growing conditions such as proper watering and fertilization is also essential in promoting its health and resistance to diseases and pests.
