Guide to the Rhododendron
If there’s one plant which deserves our respect, it’s the Rhododendron. It’s easily the biggest family of cultivated plant in this country and certainly one of the most historic. Just about every stately home will boast displays by the hundred and the chances are you’ve been enjoying the blooms of at least one during the last few weeks.
Rhododendrons are hardy evergreen shrubs that are easy to grow in an acid soil or in pots on the patio. They come in a wide range of shapes and sizes, suitable for a range of gardens. In Spring, the varied range of flower colour and forms make a stunning display and for the remainder of the year depending on the variety, the foliage can act as a useful screen, foil for other plants or point of interest in its own right. They will grow successfully in sun or partial shade.
There are over 1000 species of Rhododendrons and are classified into three common groups these days: Hardy Hybrids, Dwarf Rhododendrons and Yakushimanum Hybrids. Technically speaking, Azaleas are also Rhododendrons, consisting of the deciduous forms and of course those evergreen Japanese Azaleas, which have been flowering their little hearts out for the last few weeks.
Hardy Hybrid Rhododendrons are large, extremely hardy evergreen shrubs with the smaller varieties suitable for growing in large patio pots. In the spring to summer months their large flowers provide a bold splash of colour in a wide range of shades. They tend to have a rounded spreading habit, which combined with their lush green foliage, provides a useful natural screen all year round.
Many Dwarf Rhododendrons are from alpine regions. They are hardy, compact and evergreen with a mound forming or spreading habit. The evergreen leaves are often aromatic with a wide range of textures and shapes, giving interest throughout the year. The flowers are smaller than Yakushimanum and Hardy Hybrids, with the impact coming from the sheer volume of blooms produced.
Rhododendron ‘Snipe’ is a typical example of a Dwarf variety. It’s a very compact shrub which produces an absolute abundance of small light orchid pink blooms. The Yakushimanum Hybrids have the bold flowers of a hardy hybrid combined with a compact habit more suited to growing in patio pots or where space is limited.
Yakushimanum is a tough floriferous evergreen species introduced into this country from Yakushima, an island off Japan in the 1930s. In the late 1950s Percy Wiseman, nursery manager at Waterers Nurseries saw that gardens were getting smaller, so crossed Yakushimanum with larger growing hybrids to produce a range of extremely hardy compact Rhododendrons with masses of bold colourful flowers. These hybrids have made a massive impact on modern gardens and are the most popular type of Rhododendrons.