Metrosideros kermadecensis Sunninghill

Metrosideros kermadecensis 'Sunninghill' is a tall evergreen bush for mild climates. The green leaves with yellow spots of this variety of Kermadec Metrosideros are decorative all year round, and its bright red plume-like flowering is magnificent throughout the summer. Its requirements are as exotic as its appearance, as it only tolerates light frosts, which limits it to coastal and southern gardens... In cooler areas, its slow growth allows it to be planted in pots to be brought indoors in winter. It likes rich, neutral to acidic, moist but well-drained soils and can also tolerate drought once well established.

Metrosideros is a member of the large Myrtaceae family, which includes about three thousand species and dozens of genera, including the well-known Eucalyptus, Feijoa, guava (Psidium), bottlebrush (Callistemon), and myrtle (Myrtus) which gave the family its name. They are often plants of mild or tropical climates, with characteristic flowers with decorative tufts of stamens. This tree, known as ironwood because it is so hard, is native to the volcanic Kermadec Islands, discovered by a French officer of the Royal Navy off the coast of New Zealand. In these latitudes, it is a tree that can reach over 15m (49ft 2in) in height with a trunk diameter of 1m (3ft 4in) or more.
In our gardens in the south or on the Atlantic coast, Metrosideros kermadecensis will form a much smaller bush: 3m (9ft 10 n) high and 2m (6ft 7in) wide after 10 years, as its growth is slow. At maturity, it can reach 6m (19ft 8in) high and 5m (16ft 5in) wide, or even more, so this should be taken into account when choosing its location.

This bush has small evergreen leaves that are 3 to 5cm (1.2 to 2in) long, a beautiful bright green colour, with a central yellow spot with more or less irregular contours. This bright and decorative foliage all year round provides a contrasting backdrop for the superb bright red flowering that lasts throughout the summer. These flowers are grouped in clusters at the ends of the branches and display tufts of scarlet stamens about 3cm (1.2in) long, clearly visible with their tousled appearance.

Adapted to neutral to acidic soil, this plant appreciates a certain level of humidity but in well-drained conditions, excess water can be fatal, especially in case of frost. It is indeed quite sensitive to cold, it can withstand temperatures around -3/-4°C (26.6/24.8 °F) and its foliage is damaged below that. It can resprout from the stump down to about -6°C (21.2 °F) but not more. These data are indicative, as in case of excessive soil moisture or cold winds, its tolerance can be significantly reduced.

Its limited hardiness restricts its cultivation to milder coastal areas, where it will find its place in seaside gardens as it is resistant to salt spray.
In colder regions, it will need to be grown in large pots to be overwintered frost-free. Its slow growth and small annual size will allow it to be enjoyed for many years, like an orangery plant.

Metrosideros is a great choice for Mediterranean or exotic gardens. Its tropical appearance will allow it to be used in "exotic" beds alongside other plants with a distinctive aesthetic. The palm tree Syagrus with its port and leaves resembling a coconut tree will be perfect in the background, ideally in multiple specimens to enhance the "southern seas" effect. The oversized foliage of hardy banana trees or the bird of paradise with its flowers so evocative of the tropics will also be good companions. And if the combination of green, yellow, and red colours is not enough, why not add some blue and cream white with the delightful Eucalyptus 'Baby Blue'.