JARS v46n1 - The Golden Quest

The Golden Quest
Seeking Hardy Yellows for Long Island
Werner Brack
St. James, New York

For many years hybridizers in the New York area have worked toward an elusive goal, a truly hardy yellow with good color, good form and good foliage. Many years ago, one gardener on eastern Long Island (in Watermill) succeeded in growing Exbury's 'Crest' much to other gardeners' envy. The nearness to the water gave him a milder climate than most of us enjoy. 'Crest' is a cross of Rhododendron wardii , and it was with a new wardii cross that Long Island hybridizers really began the new quest for gold. This pioneer plant was Don Hardgrove's 'Golden Star' ( R. fortunei x R. wardii ), not introduced until 1978 but in use for many years before that. It is an easy to please and vigorous plant; the truss is fairly good, although it is not a particularly strong yellow and is not reliably bud hardy except in the intermediate coastal area. 'Golden Star' is the best known and most widely grown yellow on the East Coast. Mature plants may be seen in many gardens, including some on the ARS Annual Convention tours in May. Planting Fields has a good plant, and there is one in my own garden.

R. 'Golden Star'
R. 'Golden Star'
Photo by Martha Prince

Most, if not all, West Coast yellows are disappointing performers here, either because they are not sufficiently hardy to withstand our winters or because they cannot stand our hot, humid summers. As a result several hybridizers are working on producing yellow hybrids which combine the adaptability of 'Golden Star' with flower quality of the superior West Coast hybrids. It is also hoped to improve the bud hardiness of 'Golden Star'.

Of course, each hybridizer pursues this goal in his own individual way. The other yellow most used in current efforts is Phipps #32, which is itself probably a descendant of 'Golden Star'. It is listed in the Phipps records as "Hicks Hardgrove yellow x yellow seedling"; it is likely that this Hicks Hardgrove yellow is the same cultivar later registered as 'Golden Star'. Phipps #32 is a compact grower with a fine truss of good yellow flowers and is very floriferous. It is difficult to propagate, however, and to the best of my knowledge only three plants of it are in existence.

R. Phipps #32
Phipps #32
Photo by Diana Church

As Seed Exchange chairman for our New York Chapter since 1985, I have observed that, year after year, crosses containing Phipps #32 account for over 10 percent of all crosses sent to me. Both 'Golden Star' and Phipps #32 figure prominently in many of the most promising crosses.

To improve hardiness and adaptability, many of us have used such hardy Dexters as 'Janet Blair', 'Scintillation', AE, and 'Dexter's Orange', plus R. yakushimanum . Often these crosses are made with the more tender West Coast hybrids, such as 'Beautiful Day', 'Holy Moses', 'Pacific Gold', 'Lackamas Gold' and others. Usually these first generation hybrids will not show the wanted results, mostly because the color intensity is diluted. In the second generation, these hybrids are crossed with our eastern yellows; hopefully, this will produce the desired result. A good example of this approach is Dick Murcotts' 'Mary Guthlein' ('Scintillation' x 'Inamorata') crossed with the Hardgrove hybrid [ R. fortunei x ( R. wardii x R. dichroanthum )]. This produced a fine plant with rich yellow flowers and a good full truss. A somewhat similar hybrid of my own, 'Janet Blair' x [ R. fortunei x ( R. wardii x R. dichroanthum )] crossed with Phipps #32, also shows great promise.

Bud's yellow
[('Inca Gold' x R. yakushimanum F.C.C.) x R. wardii KW]
x 'Dexter's Orange'
Photo by H.C. Gehnrich

Another example which produced a very good yellow hybrid, with excellent foliage and plant habit, is [('Inca Gold' x R. yakushimanum F.C.C.) x R. wardii KW], of Jack Rosenthal, crossed with 'Dexter's Orange' by Frank Arsen. A fine plant of this cross has been raised by Bud Gehnrich and is usually just called "Bud's yellow". An excellent example of a first generation hybrid was produced by John Nicoella; this is R. yakushimanum x Phipps #32. It is a vigorous, compact plant, with fine foliage and flowers, somewhat similar to 'Bob Bovee'.

Phil Waldman's pride and joy is a cross of ('Catalgla' x 'Crest') with Dumper's yellow R. fortunei . Fine yellow flowers in a large truss, combined with vigorous, upright (but dense) growth, make this plant a standout performer.

('Catalgla' x 'Crest') with Dumper's yellow
R. fortunei
('Catalgla' x 'Crest') with Dumper's yellow R. fortunei
Photo by George Woodard

Of course there are probably other fine yellow hybrids I am unaware of, as yet. The list is growing every year. Although many of them may not ''make the grade", I predict that by the turn of the century there will be several commercially available yellows rivaling the finest West Coast hybrids. Meanwhile, the quest for the perfect, bright, hardy yellow rhododendron, with good foliage and good form, continues. At the convention on Long Island, in May, you will be able to see the progress we have made so far.

Werner Brack is the president of the New York Chapter. The Brack garden will be visited by members attending the ARS Annual Convention in May.