QBARS - v20n2 A Progress Report on R. arboreum Seed Distributed in 1963

A Progress Report On Rhododendron Arboreum Seed Distributed In 1963
R. L. Ticknor, Aurora, Oregon
North Willamette Experiment Station
Oregon State University

In the April 15, 1963 Bulletin, seed of Rhododendron arboreum was offered for free distribution by Oregon State University's North Willamette Experiment Station. Dean F. E. Price of the College of Agriculture had received the seed from an O. S. U. alumnus, Mr. Ray G. Johnson, who is an agricultural attaché in India. This seed was gathered in December of 1962 at Simla, India, by Mr. Santokh Singh, at an elevation of 6000-7000 feet from red-flowering plants 12 to 20 feet tall.
A total of twenty-five requests: 10 from Oregon, 6 from Washington, 2 each from California, New York and Pennsylvania, and one each from British Columbia, Maryland and New Jersey were received and the seed was mailed May 15, 1963. In August 1965 a questionnaire was mailed to the people who had requested seed. A follow-up questionnaire was mailed in October 1965 to those who did not return the first. Twenty-three answers were received, an extremely high percentage showing the cooperative spirit of the members of the American Rhododendron Society.

The questions on the questionnaire and the answers are as follows:

Did the seed germinate? Yes 21 No 2
Did the seedlings survive transplanting? Yes 15 No 6
Are the plants growing outside? Yes 10
Are the plants growing in a greenhouse? Yes 5

Approximate number and size of plants which have survived the winter out-of-doors:

California 29 5"-10"
Pennsylvania None
Oregon None
Oregon None
Oregon 2 1"
Oregon 3 of 100 6"
Oregon 50 (many given away) 6"
Oregon 300 3-7"
Washington 63 or 50% 3-7"
Washington 60 4-7"

The number surviving was apparently governed by climatic conditions, since the places where seedlings are growing in larger numbers are California or the Oregon or Washington coasts. During the winter of 1964-65 the temperature dropped to 6° F in the Portland area causing heavy winter losses away from the coast in Oregon and Washington.
It is hoped that the plants which were kept inside the first two winters are out-of-doors this winter. In addition to the plants previously reported, there are 40 plants from 6-12 inches at the experiment station which look good so far this winter (mid-February). Possibly among the surviving seedlings there will be one or more plants of good garden value at least in mild climate areas. The surviving plants may also serve in the future as a source of pollen for hybridizers of red rhododendrons. Many of the ironclad red hybrids are supposed to have R. arboreum in their backgrounds. With the newer white forms of R. catawbiense , it may be possible in the future to produce hardy reds with less blue in the color.