Rhododendron x gowenianum - Gowen's Azalea

Rhododendron x  gowenianum, still very rare in cultivation, is an ancient hybrid variety between an azalea and a rhododendron. This plant charms with its delicate and original flowering, made up of a multitude of small mauve to pink star-shaped flowers that perfume a whole section of the garden. In late spring, it is a real pleasure to see them bloom in large numbers on its beautiful rhododendron leaves. With its lovely rounded habit and modest stature, this bush thrives in partial shade and acidic soil, making it perfectly suited for small spaces and container gardening.

Rhododendron x gowenianum is a result of cross-breeding between an evergreen Rhododendron and a deciduous azalea, carried out in the United Kingdom before 1825 by James Robert Gowen. Its parents are the Rhododendron periclymenoides or viscosum and the hybrid R. catawbiense x ponticum. It is a hardy evergreen shrub (up to -15°C), which performs well in our cool and humid temperate climates.

This Rhododendron forms a well-branched bush with a dense and globose habit, which measures about 1m (3ft 4in) in all directions at the age of 10 years. In optimal growing conditions, it can reach 1.50m (4ft 11in) in height. Its growth is slow. Its flowering, full of charm, takes place in early June, depending on the climate. The flowers, 2.5 to 3.5cm (1 to 1.4in) wide, gradually change from light mauve to lilac and soft pink. They have a funnel shape and are gathered in spherical terminal clusters, each of which can have 36 to 48 flowers. Their scent is intensely sweet. The foliage, more or less evergreen in winter, is composed of large, simple, elliptical leaves with entire margins, arranged alternately on the branches. Their colour is a fairly dark green with a slight shine. Some leaves fall in winter, some dry up in spring, while new shoots develop. Rhododendrons have a shallow root system, which should never lack moisture, but they fear stagnant humidity that suffocates them.

Rhodoodendrons thrive in cool and humid climates, with marked winters, planted in humus-rich and acidic soil, such as heather soil. Under these conditions, they are beautiful evergreen shrubs for borders or flowering pots, attractive all year round. They happily accompany heathers, Japanese maples, or their Chinese relatives, the changing colours of which vary with the seasons, as well as Japanese camellias and their graceful autumn-flowering cousins, the often fragrant hybrids of C. sasanqua. The gowenianum hybrid, which forms a beautiful rounded bush, allows for playing with heights and filling in the spaces left between large heather shrubs. It will work wonders in large borders, but also on the terrace or balcony, in a carefully chosen large pot.