More Notes on R. 'Mrs. Betty Robertson'
I write with reference to your note on the Rhododendron illustrated on the cover of the July issue of the American Rhododendron Society Bulletin.
It is always difficult to identify exactly a hybrid of a particular type from a color photograph-particularly a campylocarpum hybrid of which there are so many very much alike.
However, it may well be that the plant illustrated is, in fact, Mrs. Betty Robertson. This variety is, as you say in your note, wrongly named in the 1952 Rhododendron Handbook. On the other hand, it is listed in my catalog and also in that of the Knaphill Nursery Company. My own description is "yellow fringed pink" and it is the same plant as that grown at Knaphill, although they give the same description as in the 1939 Handbook. It is a good campylocarpum hybrid having a flower almost exactly the same as that of R. 'Margaret Bean' (campylocarpum X 'Esmaralda') but without the bad habit and yellow foliage of that variety. The coloring of both being cream yellow with an edging of pink to the petal. The foliage of R. 'Mrs. Betty Robertson' is somewhat similar to that of R. 'Harvest Moon' but the habit is more bushy. To the best of my knowledge, it was raised by the Boskoop firm of M. Koster and Sons and is of the same group as R. 'Harvest Moon', R. 'Zuyder Zee' and R. 'Adriaan Koster'. The British gardens and no doubt Mr. Peter Koster - who is now in charge of the firm - could verify the plant in question.
West End, Nr. Woking Surrey, England.
I noticed in the Quarterly Bulletin of the American Rhododendron Society (July 15, 1955) the puzzled remarks of the Editor about the description of R. 'Mrs. Betty Robertson'. I have been equally puzzled for some time, and just recently have I found the correct descriptions. In the edition Rhododendrons En Azaleas by Herman Grootendorst I found the following: "R. 'Mrs. Betty Robertson', pale yellow with some pink flush, turning to cream, red center, R. campylocarpum hybrid developed by Koster." Although the author does not say so I rather imagine it is out of the same cross as R. 'Diane', R. 'Adriaan Koster' and R. 'Harvest Moon', these were also developed by Koster. The main portion of the book is in Dutch, but there are plant lists in English and German. I think it is well worth having and is of interest. The name is Rhododendrons En Azaleas published by Vereniging Voor Boskoopse Cultures, Boskoop, Holland.