This genus of plants has about thirty species of evergreen trees and shrubs, originating in the Hawaiian Islands, Australia and New Zealand. They have an erect habit, widened, with a very dense and branched crown; the leaves are oval, dark green, covered with a thick gray-whitish down. From April to the end of the summer poducono terminal inflorescences, consisting of brightly colored flowers, red, pink, orange or yellow, with a feathery appearance, very particular; the flower buds are covered with a light whitish down. In nature these plants can reach majestic dimensions, close to 15-20 meters, cultivated in our gardens, they remain more modest in size, 1.5-2 meters, developing quite slowly.
THE Metrosideros they are plants that, in natural, can reach remarkable heights, but which, when cultivated, do not exceed 2 meters, so that they can also be planted in pots.
The best exposure for these shrubs is in a sunny place, or in partial shade, guaranteeing them at least a few hours of sunshine.
These plants don't like intense cold, although some species can withstand temperatures a few degrees below zero, it is best to put them in a sheltered place from the cold, for example near a wall of the house; in areas where winters are very cold the plant must be covered with TNT, or, if cultivated in pots, kept in a cold greenhouse.
These plants are rather resistant, but from March to October it is necessary to water them regularly, letting the soil dry between one watering and another, to avoid the formation of stagnant water that could compromise health; metrosideros can withstand short periods of drought, but they prefer a slightly damp soil, so it is good to remember to supply water even in the cold months, at least once a month, waiting for sunny days.
At the beginning of spring supply the plant with a slow release granular fertilizer for flowering plants, practice a second fertilization in autumn.
Metrosideros prefer loose and well-drained soils, quite rich in organic matter and possibly with a slightly acid reaction; the potted plants should be repotted every 2-3 years to allow a correct development of the root system. The ideal mixture for the soil in which to plant these plants is composed of peat, soil, pumice and organic substance.
These plants can be multiplied through seeds or cuttings. At the end of summer the flowers give way to woody capsules, which contain many small seeds, which must be sown immediately in a hot seedbed, or in spring; generally germination occurs in very low percentages, and seed plants develop very slowly. Usually it is preferred to propagate these plants by cutting, late in spring, or in January-February in a temperate greenhouse.
Metrosideros: Pests and diseases
The plants are quite resistant but it is good to pay attention to aphids and mites that can hit the leaves and buds. For this reason it may be advisable to intervene with preventive treatments at the end of winter, or when you notice the signs of their presence, but always before the plants have bloomed.