Overview
Metrosideros pumila (Heller) Hochr. is a species of flowering plant in the myrtle family, Myrtaceae. It is also known by its common names, 'Alpine Pohutukawa' or 'Snow Totara'. This plant is native to New Zealand and can be found growing in sub-alpine regions.Appearance
Metrosideros pumila is a low-growing shrub that typically reaches a height of 30-50 cm. Its leaves are needle-like, with a length of 1-1.5 cm and a width of 1 mm. The leaves are arranged in whorls of 4, with each leaf forming a vertical column around the stem. The flowers are small and white, with a diameter of approximately 8-10 mm. They are arranged in dense clusters at the ends of the branches.Uses
Metrosideros pumila is often used as an ornamental plant in rock gardens, alpine gardens, and as a groundcover. It is well-suited to growing in cold and windy regions. This plant is also used in traditional M?ori medicine for its astringent properties.Cultivation
Metrosideros pumila prefers well-drained soil that is moderately fertile. It should be planted in a position that receives full sunlight and shelter from strong winds. This plant requires regular watering, particularly during hot and dry weather. It can be propagated by seed or cuttings.Light Requirements
Metrosideros pumila requires full sun exposure for optimal growth. This plant cannot survive in shady areas as it needs a lot of light to photosynthesize adequately. When planting, ensure that the area receives at least 6 - 8 hours of direct sunlight. Failure to provide enough sunlight may lead to stunted growth and a reduction in the number of flowers or fruits.
Temperature Requirements
Metrosideros pumila is native to tropical and subtropical regions and prefers warm temperatures. It grows well in temperatures ranging from 20 - 30°C and cannot tolerate frost or extreme cold. If grown in cold regions, you can consider planting it in a greenhouse or indoors. Ensure that the temperature is consistent throughout the day and night.
Soil Requirements
This plant is adaptable to many soil types but thrives best in well-draining soils that are rich in organic matter. A pH range of 6.0 - 7.5 is ideal for optimum growth. Additionally, ensure the soil is not compacted, and there is room for roots to grow. Waterlogging can cause root rot and lead to stunted growth.
Cultivation Methods
Metrosideros pumila, commonly known as the dwarf 'Ohelo, is a small evergreen shrub that belongs to the myrtle family. It grows up to a height of 20 cm and spreads to a width of 1 meter. It is usually propagated from seeds or cuttings. To cultivate 'Ohelo, plant the seeds or cuttings in a mixture of loam, sand, and peat moss. The plant needs to be placed in partial shade or full sun with good drainage. 'Ohelo grows well in areas with cool temperatures and high humidity.
Watering Needs
Metrosideros pumila requires moderate watering. It can tolerate dry conditions for a short period, but it cannot survive under waterlogged conditions. During the summer, the plant needs to be watered regularly, and the frequency of watering should be reduced as winter approaches. Check the moisture level of the soil frequently and maintain a consistent level of moisture.
Fertilization
The dwarf 'Ohelo does not require excessive fertilizing. Fertilize the plant three times a year during the growing season. Apply a balanced fertilizer with equal amounts of nitrogen, potassium, and phosphorous. Avoid over-fertilizing since excessive nutrients can cause the plant to grow weak and spindly.
Pruning
To keep the plant healthy and looking attractive, it is essential to prune it regularly. Prune the plant to remove dead or damaged leaves and to control its shape. Metrosideros pumila is a slow-growing plant, so pruning should be done sparingly. Cut back the tips of the branches to encourage bushier growth, but avoid cutting back to old wood which can weaken the plant. Prune the plant in late winter or early spring to prevent damaging the tender new growth in the other seasons.
Propagation methods for Metrosideros pumila
Propagation of Metrosideros pumila can be done through various methods. Some of the commonly used methods are:
Seed propagation
Seeds of Metrosideros pumila are collected during the flowering season, which usually lasts from November to January. The seeds are then extracted from the flower capsules and sown in a well-drained potting mix. The potting mix should be kept moist but not waterlogged. Germination of seeds usually takes around four weeks.
Cuttings
Cuttings are taken from mature stems of Metrosideros pumila during the growing season. Cuttings should be around 10 cm in length and taken from healthy plants. The cuttings are then dipped in a rooting hormone and inserted into a potting mix made of equal parts peat and perlite. The potting mix should be kept moist and the cuttings should be kept under shade until they develop roots. Once the cuttings have developed roots, they can be transplanted into individual pots.
Division
Metrosideros pumila can also be propagated through division. This method is best used for mature plants that have developed a large clump of stems. The clump is carefully dug out of the ground and divided into smaller sections, each with an equal number of stems. Each section is then planted in a well-drained potting mix and kept moist until new growth appears.
Propagation of Metrosideros pumila is relatively easy and can be done using any of the above-mentioned methods. It is important to maintain adequate moisture levels and provide appropriate growing conditions for the newly propagated plants to establish successfully.
Disease and Pest Management for Metrosideros pumila
Metrosideros pumila, also known as the dwarf ‘ohi‘a lehua, is a small, evergreen tree that is endemic to Hawaii. This plant species is generally resistant to many pests and diseases, however, a few pests and diseases may occasionally affect the plant. Quick identification and management of these problems can help keep the plant healthy and thriving.
Common Diseases
One of the common diseases that might affect Metrosideros pumila is the sooty mold. Sooty mold is a black, powdery fungus that grows on the surface of leaves and stems. It is caused by honeydew excreted by sap-sucking insects such as scales and aphids. To manage this disease, it is important to control the insect infestation by washing plants regularly with soap and water or insecticidal soap. Additionally, pruning infested branches can also control the spread of the disease.
Another common disease is leaf spot, which is caused by a fungus that forms small lesions on leaves. The spots may be yellow, brown, or black, and the leaves may eventually fall off. Leaf spot can be managed through sanitation, by removing and destroying fallen leaves. Fungicides can also be used to manage this disease if it becomes severe.
Common Pests
The Metrosideros pumila is susceptible to infestation by several pests, including scales, mites, and aphids. Scales and mites often feed on plant sap, resulting in yellowing and wilting of leaves. Aphids also damage plants by feeding on tender leaves, leading to leaf distortion.
To control these pests, it is important to prune infested branches, and to use insecticidal soaps and oils, which can be effective in managing both mites and scales. Aphids can be controlled by washing plants regularly with a strong stream of water or insecticidal soaps. Ladybugs and lacewings are natural predators to aphids and can be introduced to the garden to control them.
Preventive measures such as regular watering, proper fertilization, and appropriate use of mulch, can also help in keeping the Metrosideros pumila tree healthy, strong, and resistant to pests and diseases.
