Room for rhododendrons

Press, 25 May 1984, Page 10

Room for rhododendrons

Akrdener’sl! W DIARY

Derrick Rooney

The clearing away last week-end of a geriatric escallonia hedge (at the cost of sweat, blood from a punctured finger, a bent crowbar and a shattered spade-handle) has provided a large, clear space for some new shrubs — something I thought could not happen in my overcrowded garden. I need the space badly, because like most enthusiastic gardeners I have an overlarge stockpile of plants which just had to be acquired or propagated, even if there was nowhere to put them.

Among these shrubs, which will go into the cleared patch once I’m sure most of the couch-grass has been eradicated, are some “cast-iron” rhododoendrons — three vintage varieties (“Mars,” “Old Port,” and “Moser’s Maroon”) and “Old Copper,” the offspring of two favourites.

These are a mixed bunch, interesting not only for their own good qualities, but because some of them reflect the influence of two remarkable species which have, probably more than any others, affected the course of rhododendron breeding. “Old Port” and “Moser’s

both date back to the nineteenth century, though I have been unable to trace their precise origin.

The former is well named, for the unique dusky colour of its flower trusses, and is a bush of remarkable hardiness and longevity, properties it has inherited from its parent, the North American Rhododendron catawbiense, which was imEortant in the breeding ol ardy rhododendrons of early Victorian times.

"Moser’s Maroon” is also in this rich but unfashionable colour range, but I have so far been unable to trace its parentage.

It is an unusual rhododendron, not only for its flower colour but for the brilliance of its young growths, which are heavily flushed with red. The habit is rather straggly, but despite this, and even if it never flowered, it would be worth growing as a foliage plant — if only it were more readily obtainable. Alas, the pendulum of garden fashion is at the other end of the spectrum from these rich colours, and very few nurseries propagate these varieties now; I managed to procure them, after a prolonged search, because a Geraldine nur-

seryman flipped in his private bin to produce small plants for me. The historic significance of “Moser’s Maroon” is considerable, and its influence is felt in many gardens — it is a parent of such notable hybrids as “Romany Chai,” “Romany Chai,” “Bibiani,” “Impi,” and others which, in turn, are now producing a new generation of garden hybrids. "Mars,” another oldie which has been notable both as a plant and as a parent, is one of the many hybrids of Rhododendron griffithianum, a sumptuous but tender species from Sikkim which caused a revolution in rhododendron breeding after it was introduced to Britain in 1850. Breeders soon found that by crossing it with hardier varieties, they could create rhododendrons which combined hardiness with the virtues of Rh. griffithianum of which the most notable was a

dichroanthum with griersonianum.

All the “Fabia” clones are excellent, compact garden shrubs, growing only 2m high, and taking a long time to get there.

“Fabia Exbury” is salmon orange, “Fabia Roman Pottery” is terracotta, “Fabia Tangerine” is just that, and “Fabia Tower Court” is a blend of pink and orange. It’s not clear which one was used to produce “Old Copper.” The hybrids which have griersonianum as one parent, or which trace back to it after a generation or two, flower truss of enormous size.

The influence of griffithianum, through “Mars,” is felt in “Old Copper,” a lovely plant which has flowers of burnished coppery orange. There is also, in the breeding of “Old Copper,” a convergence with the line of Rhododendron griersonianum. This was introduced to cultivation in 1917, and flowered for the first time in Britain in 1923. In the present century it has exercised an influence on rhododendron breeding at least as large as that of griffithianum in the last.

“Old Copper’s” breeding is impeccable — “Vulcan” crossed with “Fabia,” which gives it double dose of griersonianum and one of griffithianum.

“Vulcan,” raised by Waterer Sons and Crisp and released in 1938, is “Mars” crossed with griersonianum, while “Fabia,” which is not a single clone but a number of different ones ranging from salmon to tangerineorange, is the collective name for crosses of Rh. are legion.

Famous plants among the first crosses include “Alice,” “Cynthia” (everybody’s favourite old rosy crimson rhododendron, and a plant which is seen in very many old gardens), “Mars,” “Gill’s Crimson,” and “Loderi” (all 23 clones of it). In the second generation, griffithianum was a key parent of one of the most famous rhododendrons of

all: “Pink Pearl,” which is a’ cross of “Broughtonii” and “George Hardy.” This is a stable almost guaranteed to produce a winner. “Broughtonii” is a hybrid of Rhododendron arboreum, which was also the parent of the famous, earlyflowering “Cornubia,” never surpassed among early rhododendrons. "George Hardy” combines the blood of griffithianum and the hardiest species of all, catawbiense.

Rhododendron griersonianum in its wild forms is a straggly, open bush, 2m or more tall, with large flowers in a colour unique in the genus — geranium scarlet.

Its flower buds are unusual, long and pointed, with many leafy bracts, and the presence of buds like this is often a good indication of the influence of this species.

Its offspring, which probably number in the hundreds, include at least 50 merit-award winners.

Among them are “Elizabeth,” “Tally-Ho,” and “F.C. Puddle.” One of their strong points (apart from the brilliant colours) is that they tend to flower late in the season, and thus miss the frosts.

A favourite in my garden is “Lava Flow,” whose wellnamed flowers sometimes do not open until early December. The seed parent of “Lava Flow” is didymum, another species whose virtues often go unnoticed. “Impi,” mentioned above, is also a didymum hybrid. Rhododendron didymum itself is a small bush, not too easy to grow (i.e. I haven’t done very well with it, though it is still alive — just), and in its best forms has deep, blackish red flowers. This is not a colour which shows up well in the garden. Consequently, plants showing a strong didymum influence are unlikely to be widely popular. But when seen at close quarters the colour is sumptuous.