In 1977 I purchased from a local nursery which was closing forty R. yakushimanum hybrids, 20 cm tall in pots at what seems now a ridiculous price of 40p each. These remained in pots until we moved to our present garden at Radlett in Hertfordshire in 1982 when they were planted out.
Among this collection were a group named the "Seven Dwarfs", created by Percy Wiseman, the well-known hybridizer at Waterers Nursery. In the ensuing years, these plants have grown considerably and are not so dwarf anymore! The following descriptions are of interest to those starting a rhododendron collection in their garden.
Registered 1971. R. yakushimanum x 'Doncaster'. Pale pink with a brown blotch. A very hardy plant, needs little attention and goes a long time without watering. Now measures 1.6 meter in height by 2.5 meter width.
Registered 1972. Half yakushimanum and half unknown. Pink. Awarded the HC in 1978. This is a fine plant with magnificent blooms and superb compact habit. One of my favorites, blooming in late May. Now measures 1.5 meter in height by 2.3 meter width.
Registered 1971. Only a quarter yakushimanum with much other blood in its veins; facetum, dichroanthum and griersonianum. From its appearance one would think it had no yakushimanum in it at all. A deep rich red. Award of Merit 1977, FCC 1979. A favorite at Glendoick, I have read. While this is a fine plant, it suffers badly from mildew here in the South East in our long dry summers. Now measures 1.5 meter in height by 2.5 meter width.
Half yakushimanum, half unknown. Award of Merit 1979. Peach fading to cream. This is the only true semi-dwarf plant of the group suitable for a rockery or border. It is prone to bark split caused by the late frosts after periods of warm weather here in Hertfordshire. It has fine foliage with brown indumentum, and has a superb hummock-shape with the excellent tight round yakushaimanum-type truss. Only two of the original four have survived. These now measure 1.0 meter in height by 2.5 meter width.
Registered 1972. Half yakushimanum and quarter 'Doncaster' and quarter unknown. Award of Merit 1977. The name 'Hoppy' was used rather than 'Happy' as Rothschild registered a rhododendron of this name in 1940. This is also one of my favorite in flower opening pale lavender, fading to pure white. A wonderful sight in a woodland setting. This is "The Giant" dwarf which, in time, will grow into a plant of some size. Now measure 2.5 meter in height by 3 meter width.
Registered 1971. Half yakushimanum, quarter unknown, quarter 'Doncaster'. Pale mauve, spotted brown. This is the runt of the litter which I found very difficult to grow. Despite all my efforts, the leaves always showed signs of cholorsis, and the plants lacked any vitality and slowly died one by one probably due to our very dry summers. One plant, which I gave to a friend locally, survived but in a stunted, miserable condition. I have not seen this plant for sale in the nursery trade for some years which I think speaks for itself.
Registered 1971. Half yakushimanum, quarter unknown, quarter 'Doncaster'. This is an easy vigorous plant which layers very readily, with good dark green foliage but is not to my taste as it is a rather garish red/pink which fades badly in sunlight and does not sit easily with the surrounding plants in my collection. If you do try it, I suggest placing it amongst white flowering varieties. Now measures 1.7 meter in height by 2.8 meter width.
Amongst the others in the original collection were: 'Venetian Chimes', 'Percy Wiseman', 'Golden Torch', and 'Chelsea Seventy'. The first three have proved to be excellent garden plants, very hardy, keeping their semi-miniature stature. They are beautifully compact in habit, and will fit in every well with smaller garden schemes. 'Chelsea Seventy' while having a startling flower with strong dichroanthum influence has a leggy habit with not particularly inspiring foliage.