QBARS - v10n4 A Rhododendron Summary

A Rhododendron Summary
By James S. Wells
Lecture given at a meeting of the Middle Atlantic Chapter of the ARS

Mr. President, Fellow members of the American Rhododendron Society, guests:

It is my pleasure to know many of you and I therefore, have some first hand knowledge of the truly vast weight of experience and "rhododendron lore" assembled here tonight. Because of this, I am more than usually conscious of the honor accorded me in being asked to address you this evening. It is an honor which I deeply appreciate.

I cannot pass on without some mention of the outstanding display we have seen today at Longwood. To my regret, this has been but my second visit to Longwood in 10 years and I was delighted and amazed at the massed profusion of plants so obviously growing happily and to perfection. It reminded me very much of the southern part of England from which I come, but I know now how much more it represents in horticultural effort and skill than would a similar display in England. My home town of Bournemouth is known as rhododendron country, for it is on the sea and the climate is mild without extremes of winter weather, the soil acid, rainfall good. We grow rhododendrons and azaleas to perfection and I grew up taking for granted that the tens of thousands of acres of rhododendron ponticum growing wild in the surrounding countryside and the brilliant displays of thousands of hybrids which bloom with annual regularity in the Bournemouth public gardens. With rhododendrons and azaleas everywhere, no one thought very much of them, and it was only when I came to this country and realized the problems with which both the producer and the consumer are faced that I realized how

Lucky we had been. For one thing, I had not even heard of Phytophthora cinnamomi , the fungus disease which can attack rhododendrons and particularly R. ponticum with such devastating effect. But my education was swift and complete. The sequence of events is important, because it led to my keen interest in the propagation of rhododendrons, and eventually to a complete change in our methods of production.

When I arrived at the Koster Nursery, in South Jersey in August 1946, preparations were well in hand for the first good crop of rhododendrons following the war. Thirty-two thousand excellent understocks of R. ponticum were potted in October, proceeded through the normal grafting process without incident, and about 30,000 first class grafts were set out the following spring. All went well until the summer of the second growing season, when a hot period of high humidity and high temperatures in July brought on a severe attack of Phytophthora cinnamomi and within three weeks 90% of the plants had been lost. The disease swept through the beds like a fire, and the crop which we had planned to market that coming fall was gone. To a small nursery such a loss could have been disastrous; to us it was a severe blow, and it made me realize that the Eastern United States was a far cry from the pleasant mellow climate of Southern England.

It was also obvious that something just had to be done if we were to remain in the rhododendron business. But what? I began to look around, talking to other growers to find out what they were doing, and to ask the question "Why not root them from cuttings?" The answers I received were not encouraging, to say the least. Oh yes, rhododendrons could be rooted, just one or two but never on a commercial scale. I obtained, read and quoted Mr. Nearing's excellent booklet describing what he had done with his special frames, but all the commercial growers shook their heads and said, "That's far too slow." I went to see Dr. Henry Skinner, then curator of the Morris Arboretum at Philadelphia and he showed me his leaf bud cuttings. The commercial grower said, "Sure, you can root a few, but it takes forever to make a plant." I quickly found out something which seems to be a peculiar trait of commercial nurserymen everywhere-if it hadn't been done then it couldn't be done, and if it changed the accepted order of things, distrust it. The "dismal Jimmies" in the trade were very quick to criticize, to pull to pieces and to tell me what couldn't be done. No one seemed at all interested in what had indeed been done, and what might be done in the future.

Despite all the prognostications of usefulness and failure we commenced intensive experimentation early in 1948, with the avowed intention of trying to propagate all rhododendrons from stem cuttings. Over a period of five years we slowly unraveled most of the important details associated with the successful rooting of a' fairly wide range of varieties. When these details are presented now they sound extremely simple, but it is astonishing just how difficult it is to establish these things when nothing is known. For some time all moves that you make have to be pure guess work and only when results can be evaluated and related to the procedures used is some of the guess work removed.

We started with the easiest plant R. "Roseum Elegans," and worked with this until we understood fairly well what was needed. With this data as a base, our efforts were slowly extended to more and more difficult varieties, testing each for timing-by far the most important single factor-hormone treatments, type of cuttings and so on through the maze of complexities which go to the successful propagation of any specialized plant. Many times we ran into a blank wall of failure, and then, and only then did we attempt to apply some technique, some change in method which might enable us to overcome this lack of response. I would like to stress this procedure because there seems to be some thought that I am a person who relies entirely upon potent hormones, mist lines, and other similar paraphernalia to obtain results. Let me say emphatically that with rhododendrons, and indeed with every plant in which I may be interested, my approach is to start in the simplest possible manner, and only when the simple methods fail do I consider using techniques of steadily increasing complexity until success is achieved. I believe very strongly that the best method is the simplest method, and that the best plant is the one that can be produced under conditions as close as possible to those in which the plant normally grows. However, if a plant or a variety defies propagation in a simple way then I am ready to throw the whole "bag of tricks" into the problem to achieve success.

There is perhaps some confusion in many growers' minds as to exactly the normal set-up of a greenhouse, with bottom heat, double glass and fully enclosed benches as being far from simple, and certainly nothing like the normal conditions under which most plants prefer to grow. Even Mr. Nearing's frame, which is apparently simple, requires careful, even complex construction, although I believe that the underlying principles upon which his methods depend are simple. On the other hand, an open bench in a greenhouse with a mist line overhead, or a line right out in the open field provides far less complex conditions, which are much closer to those under which rhododendrons grow naturally. Yet in the average grower's mind the first set up is a simple one, because he is used to it and knows how it works, while the latter is "complex" -"newfangled" and therefore not simple, and certainly not to be trusted.

But to return to our testing once more. As a result of five years work we established certain simple rules which enabled us to abandon grafting entirely in the season 1952-3 and to produce just over 60,000 cuttings in a wide range of varieties. I thought that you might be interested to see some of these details illustrated, and I therefore, have a set of slides which I will now show. It is my intention to tie in these details with my later remarks.

Now as you will see from the foregoing, plants propagated on their own roots certainly grow well, and indeed we found that in every instance they grew better than did plants raised from grafts. Some Dutch growers are now criticizing own root plants on the what is a "simple" method of propagation. For instance, I would consider grounds that they will not bud so readily, particularly in the first two or three years. This is correct, and it is a simple illustration of the extra vigor to be found in plants propagated in this way. As the plants grow older they tend to calm down-as indeed do most of us-and then they flower as well or perhaps slightly better than do grafts. This criticism cannot be a valid one, for propagation from layering is a method which has been used for years with great success. However, the final answer is that the Dutch growers are at this time becoming extremely active in production from cuttings.

But perhaps more important than the vigor of growth, we found that cuttings grown plants were practically immune from the dreaded Phytophthora disease. I say "practically" because they are not completely immune. Under ideal conditions for the disease, perhaps 5% of the plants will succumb. It is not my intention to go into cost accounting here this evening, but from intense study, one of two figures are engraved on my memory and I would like to quote them because they will perhaps highlight the importance of this work. Our cost system enabled us to tell exactly how much each plant cost to grow and naturally when a plant died anything that had been spent on that plant had to be absorbed by those that were left. In the year 1949-50 each two year old rhododendron on our nursery that had been raised by grafting had cost us $6.04 each, while each plant that had been raised from a cutting had cost us $.56 each. We are selling grafts wholesale for less than half what they had cost us to grow-an impossible situation which provided the final impetus for research into other methods of propagation. However, it was clear that if we could succeed in producing good stocks of plants from cuttings we could eventually afford to lower our prices and this I see coming about at this time. Since 1952 many people have become active in the production of rhododendrons from cuttings and one can see now the effect this is having on prices. Despite any argument to the contrary, I think this is good. In fact, I think we can say with reasonable accuracy that the bottleneck of high production costs has been eliminated and that this problem licked, the way is now wide open for a really tremendous advance in the general acceptance of rhododendrons by the "man in the street."

I wonder whether we are fully aware of the very real changes which are coming about in horticulture generally and the basic cause for them. Crowded highways have made motoring something less than a pleasure, while the general advent of TV has changed the habits of people, tending to keep together in the home much more than they used to be. The automobile is no longer a plaything, but has become a somewhat less than safe means of locomotion, and the family is finding an ever widening horizon of home pursuits which tend to keep them together. It is only natural that horticulture, in its widest sense, should be at the forefront of these changes.

In every garden magazine we see articles dealing with various aspects of home and garden development for gracious living. The outdoor living room patio cooking, climate control all these and many more catch phrases add up to a very real and fundamental alteration in the habits and customs of the people.

Well, what has all this to do with the American Rhododendron Society, you may be asking. In my opinion, it has a great deal to do with us, because probably for the first time since the introduction of rhododendrons to our garden it is possible for these plants to come down from their rather rarified atmosphere and to take their rightful place among the wide range of horticultural material available to the home gardener at a reasonable price. There is a very definite connection between the work of the plant propagator which is resulting in ample stocks of well grown plants, and the needs of an ever expanding horticultural public. It seems to me that if ever there was a psychological moment for a real fundamental development of. horticultural interest and knowledge, this is it. The need is there, the knowledge is available, and we the American Rhododendron Society ought to grasp this splendid opportunity with both hands, and instigate a program designed to aid and abet these general developments to the specific advancement of the plants in which we are interested.

I would like to digress for a moment to show how this procedure has been followed by a sister group, the American Holly Society. I recall very clearly being told in 1947 that Ilex opaca was not worth growing commercially. There was no demand for it I was told, and indeed at that time there was none. Well, what do we see now? A plethora of varieties and a vast amount of interest which is gathering momentum year by year. We have a recent book specifically devoted to hollies, and many nurserymen who grow no other plant. One enthusiast has named his place "HOLLY BY GOLLY" which explains itself. How has this change come about? In my opinion, it is largely due to the happy combination of need for this plant material, coupled with the efforts of the American Holly Society, for they have gone out of their way as an active group to put holly on the map. Now, I would not have you infer from these remarks that I think the American Rhododendron Society is in any way lacking in effort. One has only to glance through the splendid book, Rhododendrons just off the press to see how much valuable work is going on everywhere. But it is my carefully considered opinion that an exactly similar situation exists with rhododendrons at this time as did with Ilex a few years ago. Therefore, I repeat that I think the time is absolutely right for this Society to grasp the situation firmly, and direct it to the advancement of horticulture in general and rhododendrons in particular.

How can this best be done? The key to this problem is, I believe, in planned direction. Now the suggestions I am going to make have the background of my original horticultural training in England. In that county we are fortunate in having the Royal Horticultural Society which is accepted both by the trade and the amateur as being the arbiter of all that is excellent in horticulture. The plant breeder strives to the utmost to develop a plant which will justify a First Class Certificate from the R. H. S. than which there is no higher commendation. The gardener or the consumer is equally aware of the value of a plant which has received such an award, and is ready to pay a premium price to obtain it. This happy combination depends primarily upon the very high standards established by the R. H. S. which are maintained with scrupulous attention to detail.

Because of the geographic differences between England and the United States, it becomes almost impossible for any one organization to cover this country in a similar manner. In many ways, the American Horticultural Council is attempting to do this with considerable success, and it is my hope and belief that when more people get behind this organization and give it the support it deserves, it can become a clearing house for horticultural knowledge and can establish through its unit societies a set of standards on a very high level.

Any plan to publicize and to popularize rhododendrons and azaleas, should, in my opinion look far ahead into the future, at least 25 years ahead, and should work on a long range program designed to achieve certain well defined objectives. These might include the following:

  1. Horticultural education of the gardening public, with particular reference to the correct use of ericaceous material.
  2. A survey of available varieties in both rhododendrons and azaleas to determine (A) the horticultural merit, and (B) the hardiness of each.
  3. The establishment from the survey of a basic list of suitable varieties for various climatic zones, and the elimination of duplicates and unsuitable varieties.
  4. The establishment of test gardens designed to supplement information obtained from the survey and to maintain plantings of standard varieties against which new varieties could be tested and judged.
  5. The importation of new varieties and the testing of them in the test gardens against these established standards.
  6. A planned breeding program, designed to aid all those keen amateurs and professionals already engaged in this work. The purpose here would be to prevent duplication of effort, and particularly to provide a "pollen bank" from sources throughout the world, and thus to make available to all bona fide breeders pollen of certain varieties which it would otherwise be difficult or impossible for them to obtain.
  7. The testing of new cultivars raised by these breeders against the accepted standards. The selection of outstanding varieties and ultimately the distribution of propagating material to registered producers.

None of these proposals are new, or revolutionary and for all of them we have before us today, examples showing how well similar proposals have worked for other plants and groups.

I have put horticultural education at the head of the list, because I feel this to be of the first importance. The best gardener is the knowledgeable gardener, and we should make every effort to see that the home owner who wants to use our plants can do so properly and with every assurance of success. To make this certain, specific cultural information should be simply and clearly told when ever opportunity offers, and repeated time and time again. It might be presented in a variety of forms, but all should be directed to achieve good rhododendron culture in the average home garden.

Next, we should act as a clearing house for information which we should provide as a concomitant with the educational program. If a man writes in from Buffalo as a result of reading an article in the Flower Grower and says "I am fired with enthusiasm for rhododendron and azaleas. Will they grow here, and if so what varieties should I plant"? we should be able to give him a clear cut answer. Better still, we should provide that answer for the editors of Flower Grower to use in advising their readers. The answer to the man in Buffalo will obviously differ from that sent to a man in Williamsburg or Denver, and to obtain precise data to answer these queries would require a great deal of sifting of information. Relatively rapid results can be obtained from a survey similar in character to that conducted on lilacs by John Wister and his committee, but the testing program in established test gardens would be necessary for the long range program. Certainly, some drastic clearing out is long overdue, for if ever there was a hopeless mess it is, in my opinion, in the list of evergreen and semi-evergreen azaleas. With something over 700 named varieties, how can the nurseryman let alone the home owner, decide what to grow. To all these questions, and particularly to the vexed question of hardiness we should attempt to provide answers. In doing so, we should be courageous enough to come out with flat statements both of commendation and condemnation, and, of the two, I would think that condemnation, at least in the early stages, would be the most valuable.

With the testing program organized and under way, and with the establishment of a bedrock of sound varieties as standards against which to judge future developments, we should embark upon a wide program of importations from breeders throughout the world, and concurrently, the breeding of new varieties from the best that is available in this country. As both these efforts produce results, the new plants would be tested and evaluated against the already established standards. A breeding program, designed and directed through a central agency could help the splendid work of the individual plant breeder by eliminating duplication of effort, and by coordinating work now going on in many parts of the country. We all know of the exceptional work of people like Joseph Gable, for whose plants and work, I, along with countless other people, have the highest regard. These achievements have been made under difficulties which are inevitable when one man sets out to breed a new plant, particularly a plant which requires the time a rhododendron does before results can be seen. Valuable assistance which could both speed and simplify the breeding program of any individual could come from such a plan as I have in mind.

You will note that I have continued to stress the need of planning, for direction, for control, if you will and I do so being fully aware of the distrust with which the average American views anything that smacks of control. Having come through the war in England where one had to have a license for practically everything, I can fully sympathize with this attitude. Yet there is a difference between reasonable direction and planning, and rigid controls. It is the former that I visualize as being both necessary and desirable for such plans as I have outlined.

When one looks back on the brief history of rhododendron culture, it is truly astonishing what has been accomplished in the last 100 years. In 1815 only 15 species of rhododendrons -including azaleas-were in cultivation, and it was not until 1849-50 that Joseph Hooker began his exploration of the Himalayas. When we look around us and see what has been achieved in this comparatively short span-horticulturally speaking-we must feel a warm appreciation of the accumulated efforts of growers now gone, for they have left tangible evidence of their industry and success which we now enjoy. With nature, of which our chosen work of horticulture is but a part, there is no beginning and no end. The tapestry of nature comes to us richly embroidered with the work of countless men and women, each of whom has added his small quota to the pattern. We should be proud to know that we are members of this team, who, since the beginning of time have tended the simple things of life so that there might be a garden or a plant to gladden our hearts, and a place where confusion and strife can be forgotten.

Conscious always of the broad pattern upon which we work, we should apply our talents with thoughtful industry to add what little we may, so that the tapestry may grow in beauty and in grace to the lasting benefit of those yet to come.