Lets Keep the Facts Straight
By Warren Baldsiefen, Rochelle Park, N.J.
Rhododendron propagation of the catawbiense hybrids is not a recent achievement despite the unrelenting efforts to shroud the facts by a few newcomers to the field. To vindicate any misapprehension which may have arisen as a result of articles, lectures, and just off-the-cuff statements, usually of a self laudatory nature, let us briefly review the facts.
It would be idle nonsense to state that these rhododendrons were never rooted from cuttings until 1924 when Guy Nearing started his experiments at Arden Delaware. From the time of origination in England approximately 85 years ago when it was desired to multiply these Catawba cultivars asexually, cuttings were tried along with grafting and layering, and doubtless there was an occasional cutting that rooted. However, so impractical were the results that this method of vegetative propagation was all but abandoned as utterly hopeless. This belief remained unchanged until Guy Nearing perfected his Nearing propagating frame at Arden Delaware in 1928. Alien to the then conventional concepts of propagation, the idea and its purpose were wholly new and different-the product of a highly fertile and creative mind. To anyone inspecting a Nearing frame today there seems nothing particularly unusual in its construction and function. Many do look with utter amazement at the astounding success of the frame, but with our present knowledge of the requirements for rooting rhododendrons the frame's construction appears to be about as expected. What we fail to realize, which is of the utmost significance, is that at the time of its inception and perfection, which took the better part of four years, there were no records or previously successful methods to which Mr. Nearing could refer. He began with an idea, a conviction of purpose, and a vast amount of rhododendron knowledge. It is quite easy to understand the operation of something after it has been invented, but to be able to create is a rare and envious talent, which few possess.
To Guy Nearing must go the honor. It was he who was the first successful commercial propagator of Catawba rhododendron hybrids by cuttings. And yet today there are those among us motivated by jealousy or egotism who vituperate this notable accomplishment. We should instead pay tribute to this remarkable man, one of the few great pioneers in the rhododendron field who has left his permanent mark with us. We ought to be grateful not alone for this contribution to propagation but also for his unselfish willingness to share his knowledge and for his untiring efforts over these past 30 years to continually expand the number of rhododendron enthusiasts.
As a way of belittling the Nearing method we are confronted with the words "commercial scale." I do not know who or what determines commercial scale but it seems obvious that quantity is purely relative. A small business with an annual output of a couple of thousand plants is equally as commercial as a firm with facilities for upwards of 50,000 plants per year. The point not to be forgotten or buried under the barrage of calculated prose bombarding us is that Guy Nearing has always limited his annual output to serve his particular way of life, but he does have a pilot system which if he so desires, can be expanded to any size as our own operations demonstrate.
Also finding its way to innocent ears is the fantastic fabrication that the method is too slow and that it is impractical. The rooting of rhododendrons in about 8 weeks under conditions of artificial heat and hormones seems to be the ignominious boast, and any method requiring more time is rejected as obsolete. With our research centers, horticultural institutions and foundations continuing their momentous advances in chemistry, it may be that in years to come we will root even the most fastidious cultivars almost instantaneously or at the most, in a few days. What then? Shall we then look back to the present and claim that no one really rooted rhododendrons who required 8 weeks to do so.
Successful propagation implies more than the mere striking of roots. There must also be a uniformity in rooting and continuity of rooting, but of far greater importance is the continued health and progress of the young plants in the ensuing months. This is a major problem in many firms today particularly with the more difficult cultivars to which critical amounts of hormones and heat are applied in order to root a practical percentage of them. Cuttings do then root but a considerable proportion succumb after a few months and even up to two years. This then is not successful propagation which literally does not go beyond the propagating bench.
Let us not lose sight of the indisputable fact that the Nearing method of rhododendron propagation is unique in that the after-rooting mortalities are so few as to be virtually nonexistent. The first winter is the most critical for any newly rooted plant. In the autumn rooted cuttings, having been removed from the rooting medium and transplanted into pots or flats are set under glass in a cold frame. In over 10 years experience with the Nearing method, involving about 75,000 rooted cuttings of the large leaved sorts, we have experienced average first winter losses of from .1 to 1.0% The following year losses dwindle to 0.03 to 0.06%. This is largely due to the fact that in the Nearing method, as opposed to some other methods of propagation, there is no violation of the natural cycle of the plants. Cuttings need only respond to the seasons. In greenhouse propagation with heat for example we have a precipitation breach of the normal sequence of seasons which many rhododendrons apparently cannot adjust to. We do not haul our specimen plants into the greenhouse for the winter to force them to continue growing, for they would not tolerate this abuse, and yet this is precisely what we are expecting a tiny cutting to endure.
The proper application of both natural and synthetic hormones has enabled us to root cultivars that previously resisted the talents of the most sagacious propagators. With the advent of these auxins came a modified Nearing frame that has increased the number of clones to be successfully rooted to many hundreds. (I understand that the details of this modified Nearing frame, with blueprints, are to be published in Dave Leach's forthcoming book, "Rhododendrons of The World"). To the research specialists who made these hormone treatments possible, we owe a debt of gratitude. These men, beginning with only small fragments of knowledge on the subject, did, with infinite patience, determination, and countless experiments, finally set up a series of rough rules by which propagators can improve in their field.
It is to these pioneers who shed the first light on the subject that we owe our thanks. These men who seek no public applause or recognition are little known. Offhand I cannot recall all of them but there come immediately to mind Zimmerman, Crocker, Hitchcock, Cooper, Wilcoxen, Stoutmeyer, Grace, and, experimenting independently with a prolonged soak method, Leach. Without these men we would he no further along the road to reaching our ultimate goal of propagating all rhododendrons by cuttings, than we were in our efforts to root any rhododendrons before Guy Nearing invented his method.
Mr. Nearing's work is of inestimable significance not only for the rhododendrons it has produced to beautify our land but also for the basic principles it revealed which have had a profound and lasting influence on any method in use today.
These are: maximum aeration of the rooting medium; the wounding and shortening of the cutting to 2½ inches for better oxygen supply and higher concentration of the natural hormone, indole-acetic acid at the rooting zone: high and constant humidity in the air above and around the foliage combined with the maximum brightness without the sun's direct rays.
Attached is a list of rhododendrons propagated in our nursery by both the original and the modified Nearing methods. Many of these cultivars are so difficult to propagate that it was not until comparatively recently with the advent of the Nearing method, that they have been consistently rooted with success. We do not root all those listed 100%. If the stock plants are growing under conditions which can be somewhat controlled most of the Catawba hybrids strike between 90 and 100%. This also holds true for practically all small leaved and deciduous rhododendrons. Where it is necessary to collect cuttings from dells and woodlots, and from old plants growing without benefit of irrigation, the percentage of strike is somewhat regulated by the rainfall and other natural factors in each season.
There still exists much doubt among propagators as to the practicability of rooting the deciduous azaleas (rhododendrons) from cuttings. Most maintain it cannot be done. Listed is a cross section of many different bloods of deciduous azaleas which I have grown profitably from cuttings using the Nearing method.
The Nearing propagating frame is only beginning to enjoy a popularity which I predict will grow with each passing year. Suited to both large and small scale propagation, its use is not confined to ericaceous plants alone, and its operating expenses are negligible. Currently the Nearing frame is finding a permanent place in an increasing number of nurseries and back yards from coast to coast and even across the seas in England on one side of the world and in New Zealand on the other. This world wide use is a fitting tribute to a remarkably ingenious and benevolent pioneer in propagation whose accomplishments are thereby saluted by his grateful benefactors.
Editor's Note: Due to the limitation of Bulletin space it is regretted that the over 450 varieties listed by the author and consisting of species, English, Dutch hybrids, also those of Nearing, Gable, Dexter, and Azaleas of Exbury, Knaphill, Slocock, Ghent, and Ham varieties could not be listed in this edition