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Rose Breeding Around The World
Gardener's Chronicle and New Horticulturist, Vol. 165, No. 15. April 11, 1969
Ralph S. Moore, California, USA

Note: the word “cultivar” is frequently abbreviated in this article to simply “cv”, or the plural form “cvs”.

Any rose breeding program, if it is to really get any where, must have a plan. The aims or goals to be attained must be clearly thought out, and I am convinced that, in the final analysis, rose breeding is primarily a mental process.
By this I mean that the shortest, and usually surest, way to overcome any problems is to plan around them before the actual hybridization process takes place. One should know by observing the cultivars, species or seedlings to be used, what will or will not make a likely cross.
For example, if the object is to produce a yellow rose better than those currently available, one should first study all the likely cvs to see how well each fits into the mental blueprint of the proposed "perfect" yellow rose. And this should be further qualified by deciding whether one is going to work for a Hybrid Tea, a Floribunda, Climber, Shrub or Miniature.
Bloom size, shape, fragrance, abundance, plus such other desired qualities as vigor, plant shape, disease resistance, ease of propagation, cold and/or heat resistance, must also have their place in our mental blueprint.
Some of this knowledge can be had by study of books, and by observing them growing, or at shows.

Observation

But a good part of the breeder's knowledge must come from observations in his own garden, nursery or greenhouse over several growing seasons. The breeder must grow many seedlings, observing the best of them all the way to maturity. Even then it often happens that a cultivar's true potential as a breeding parent may not be immediately apparent.
Possibly a different combination would have given better results. It may be that a larger population of seedlings would have given a more complete picture of a given cultivar's potential. And in spite of the popularity or awards given to a cv, it just may not be a good parent. There are very few roses which have proven to be "great" parents.
Selection of breeding material is determined, at least in part, by: (1) Availability; (2) desirability; (3) probability (possibility of producing something good); (4) proven ability and (5) exploration (testing to see what a species, cv or untried seedling may produce in certain combinations).

Limitations of Breeding

All too often the path to a new cv of merit is not an easy one nor is it quickly attained. Many factors enter the picture; some may only be of academic interest while others are very real indeed.
First, one must consider the genetic potential. Do the proposed parents possess the qualities desired in the finished product? Must we deal with too many undesirable factors in order to get some of the desired ones? Might we not do better if other parents were considered?
Many otherwise desirable roses are sterile, or so nearly so, so that their use is impractical. Some are male fertile, producing good pollen which can be used to make a cross but being female sterile, or nearly so, the reciprocal crossing is impossible or impractical. This very definitely presents problems when one is working with certain specified goals in mind.
For example, many of the moss roses are sterile (at least when used as female parents), or if seeds are produced, germination may be very low or nil.
The same problem exists in working with miniature roses. Very few miniatures will set hips, and then there may be but one to three seeds per hip. Add to this the probability of poor seed germination and it can be readily realized how this fertility/sterility factor is a very real limitation of the breeding potential.
Often there are practical ways around such difficulties but they may be more time-consuming. Here the intimate knowledge of one's breeding materials can do much to contribute to the success of crosses the breeder might be considering.
As the breeder goes about the work of breeding roses for specific purposes, colors and conditions he is also aware of other factors. The color spectrum range of a cv to be used must have consideration if one is seeking new roses of specific colors and hues. Some cvs are limited in color range which we can expect in the offspring. This can be learned by actual experience in using certain cvs and at least some idea of what to expect of a cross can be gathered by carefully studying the ancestry of a known cv.

Parents

We know that certain combinations will more likely give us vivid reds or yellows, as the case may be. Also, certain parents are likely to give us plants with good to better than average foliage while others are almost sure to produce weak, poorly foliaged plants.
Then we must deal with what is termed "incompatibility". This has been attributed at times to differences in chromosome number, but I find that this may not always be true. Even using closely related cvs having the same chromosome number such as the hybrid teas (normally 28 chromosomes) other factors also appear to have their influence.
But we do meet this incompatibility between certain cvs and species, and it can present real problems. The old-fashioned moss roses generally have 28 chromosomes, yet crosses between the moss and other types of roses have not been easy and too often the resulting offspring are sterile (at least female). Again, pollen of one sort may be fertile and take well on certain other sorts yet give no hips at all when used on another otherwise fertile parent.
Other limitations on making desired crosses may involve climatic factors of heat and cold. A very good rose in one climate may be a dud in another. Years ago, the late Dr J. H. Nicolas said that "Every rose is a good rose somewhere. But that somewhere may be limited to a very few miles of its origin".
Very good roses have been bred which will do reasonably well in colder climates (with proper protection) but I feel that breeding of really good cvs for hot dry areas (desert and semi-desert) and other temperate regions has been neglected. A modern counterpart of the old tea roses might be bred for regions where extreme winter hardiness is not necessary. Other limiting factors are:

Mechanical: A flower which may be very fertile fails to produce seed because the style is too long for the pollen tube (down which the nucleus of the pollen must travel) and thus fertilization cannot take place. While I was in England last summer I was shown a very ingenious solution to the problem when I visited Gregory & Sons' nursery at Nottingham.

Time/space factor: This must always be taken into consideration for it not only includes the time of growing and otherwise preparing seed parent plants but it covers the span of time necessary to grow, test and evaluate seedlings. It is further complicated by the constantly enlarging area needed to grow several succeeding generations of seedlings, because the testing may include plants from three or more seed crops.
Time also enters in when long range crosses are made. In order to reach certain goals it may be necessary to have several lines of breeding going at the same time, the object being to eventually bring some of the best of the seedlings together in crosses combining certain traits from several parents.
This has been the method I have employed in producing many of my miniature roses so that actually as many as 20 years (or more) can go into producing a new cv. The same long range planning and effort has been used to produce a new race of everblooming bush type moss roses which, I hope, will soon be on the market.

Cost: Both. in money and effort, costs are also ever present factors in a breeder's life. Too often the gardening public has only a vague idea of the cost in time, thought and money necessary to produce a given new rose cv. They do not see the thousands of discards nor do they realize the disappointment and the cost of many a good rose which "almost made it", yet in the final countdown had to be discarded.

Public acceptance: The public has the final vote as to whether a given rose will be a winner, an "also ran" or a dud. The new rose may be better in many ways than others more popular, yet it may lack bright color, or that certain form or style acceptable at the time. Or the name or the timing may be wrong.

While most breeders think in terms of field selection of new rose seedlings my own mode of operation is somewhat different. Seedlings are not planted into the field. Instead, the seeds are planted broadcast or in rows in seed boxes in an unheated glasshouse. Sowing is usually about the first week in January and the first seedlings begin to appear a few weeks later. These seedlings will be in flower about the same time that established bushes grown outdoors come into spring bloom. Seedlings are watched and checked daily so selection may be said to begin in the seed box.
Each day as interesting seedlings attract my attention a small stake (about 4in. long) is placed alongside each plant to be further observed. Most of my rose breeding has been confined to miniatures (and to a lesser extent moss roses). Plants are marked for further study on the basis of plant form, foliage and co lour. I am always on the alert for plants which might be used for the next stop in my long-range breeding program. This has paid off as many of my most valuable breeders are seedlings selected for specific characteristics.
After seedlings have flowered, only those marked with the small stake are potted on. This may be only 10 to 15 per cent of the total seedlings. These are closely watched through successive blooming periods. Then, taking into consideration the various factors of plant, foliage, compactness, flower color, shape, doubleness, lasting quality, and fragrance, only a few are finally transferred to large pots or into discarded one gallon food tins.
All this is usually done during the seedling's first season. Cuttings are taken from the most promising selections early enough so that young plants can be grown through the winter in the heated glass (or plastic) house. This allows us to have a number of well-started plants which can be observed all through the second season. Additional cuttings (sometimes buds or grafts) are taken of the best and stock plants grown for testing and commercial propagation. We now have, or will soon have, representatives in the major rose growing countries to whom plants or propagation materials are sent.

Miniature roses

Each breeder has certain aims or goals which he would like to reach. In my own case miniature roses have long been my first love. t had long dreamed of miniatures with the bud form and array of colors to match the hybrid teas. I have been fortunate in that much of this has come to pass. Probably one half of all miniature rose cvs now grown throughout the world have originated in my nursery.
But the end is not in sight. While beautiful bud form has been attained and miniatures may now be had in colors ranging from pure white through many shades of pink, rose, yellow, bi-colors and blends—and recently lavender, there is much more to be done. In February of 1969 we introduced the first mossed miniature. While a number of my better cvs are grown in England already it is hoped that, in the not too distant future, many more of them will become available.
Other aims of my breeding program are improved sorts of miniatures which will supersede most of the earlier kinds. We need some better pink cvs. Among the better miniatures in the pink shades are 'Eleanor', 'June Time" and the very new 'Judy Fischer'.
Many of the older miniature pink roses lack fine bud and flower form and keeping quality; some are not so hardy as desired or are more prone to disease. So there is plenty of room for improvement among the pink cvs alone. We also could use cvs in all colors which would lend themselves to growing in pots as a florist item.
Next to miniatures, my interest in moss roses has grown and breeding efforts have been stepped up, the goal being to produce a new race of everblooming, bush type moss roses which can be grown in any garden exactly as present hybrid teas, Floribundas, Grandifloras and Miniatures are. Planting, spacing and care will be the same.
We have come a long way in the past 20 years, the past 5 being especially significant. We now actually have under test several potential cvs, the mossiest being in the Floribunda-moss class. Several of these have been sent out for trial. None is yet available to the gardening public but we do hope that interest in these novelties will justify the many years of effort.

Propagation

Growing techniques in our nursery are adapted to our special needs and to our climate. All of our miniatures (except miniature standards) are on their own roots, being propagated from cuttings. We believe the cutting method is best for several reasons. Cuttings can be taken and rooted all year in our climate. Outdoor winter temperatures may get down to 22° F but usually not lower than 26° or 27° F, and this for only a short time.
We do get sufficient winter cold to induce dormancy of roses, peach, plum and other deciduous plants. Some cuttings are rooted outdoors all winter in open raised beds and nursery boxes (wooden trays) filled with a sand mixture (DC Mix). These plants are grown on to saleable size in the medium in which rooting takes place.
Such plants are handled bare root and are produced in large quantities for special markets. During the winter months it may take three months to root cuttings outdoors.
However, most of our propagation is done during the warmer parts of the year using soft wood cuttings under mist units. This past season we rooted about 150,000 plants in over 60 cvs directly in pots. Part were in 2 inch. square plastic pots and part in Sin. ones.
Pots were placed directly on tables or raised beds outdoors and filled with our regular potting soil (1 part peat; 1 part sterilized loam; 1 part perlite). Soil was smoothed off by hand, moistened, and one cutting stuck in each pot. Mist was used during the day and turned off at night.
We used three types of mist heads. Two were of the simple baffle type using low water pressure. These were placed about 40in. apart over each 3ft wide bed. The third type was a small revolving sprinkler designed to be used in orange groves. These also operated on low pressure and were turned on and off as needed. Spacing was at 10ft intervals over each 5 or 6ft wide bed. Results appeared as good with these as with the regular misting heads and the cost was much less.
We are thoroughly sold on this "root-in-the-pot" method as it not only eliminates the potting labor but we found that our percentage of success was higher than with the conventional way. For example, we had been losing as high as 75 per cent of one particular cv during the rooting/transplanting/growing operations. Using our new method on this cv we grew better plants in less time and had as high as 95 per cent success. Most cvs gave us very close to 99 per cent.
Close attention to all phases, from the selection and making of the cutting through the misting/rooting and growing on routine, is important. As soon as cuttings were rooted they were weaned from the misting and a light application of fertilizer was applied to stimulate growth. From here on regular normal care was given.

Miniature standards

For our miniature standard roses we have changed our method this season, adapting the grafting technique which I had observed in England. We first root our standard stem (a long cutting with all the lower buds removed leaving a clear stem or trunk about 12 to 14in. long plus two growth buds on top) in Sin. square plastic pots as described above for bush miniatures. Then we place these potted roses in wooden trays and move into a plastic greenhouse where they are grafted. The graft is tied in with budding rubber and the stub is waxed.
These boxes of grafted plants are then place under a plastic tent inside the house for about three weeks. Grafts should be sprouting out now and plants are removed from tent, shifted into Sin. square plastic pots and placed on greenhouse benching for growing on. New growth is pinched as needed to produce a bushy top.
How do we go about determining which of the numerous promising seedlings are finally selected and made ready for introduction? I have no hard and fast rules, that is, on a points basis. But there are certain criteria or standards which help to decide which new rose will or will not be chosen.
Among these are (1) growth habit; (2) hardiness to conditions of heat and/or cold; (3) shape of the plant, including spread, habit and overall size; (4) health of plant and foliage; (5) ease of propagation, by rooting, budding or grafting; (6) production of sufficient quantities of propagation material; (7) flower quality, texture, lasting (on plant and cut); (8) bud/flower shape, color, size, quality, placement of bud/flower or bloom cluster on plant, length and strength of stem, and (9) overall effect.
I have dreams of breeding yet better sorts of miniature roses. Especially needed are better pinks and yellows. Possibly new advances in lavender will be forthcoming. I have some selections in lavender shades under observation.
Then there is the possibility of green roses; not just a rosette of foliage such as the green rose, Rosa chinensis 'Viridiflora', but real roses in soft shades of green! I now have under observation a new miniature rose selection which opens pure white then changes to soft even green which lasts for days. It is a true rose flower in all respects.
So for I have not seen in the miniatures what I would class as brown color but this also a possibility. However, any rose, miniature or large flowered, in any of these unusual colors must possess good habits of growth, plant, bud and flower form, if it is to be acceptable.
Everblooming moss roses in a range of colors, with good bud and flower form, growing on compact garden size bushes are now within reach. This will add a new dimension to rose growing and rose interest. Among my latest moss rose hybrids is a good looking yellow Floribunda with very good moss on the buds.
An interesting extra dividend with some of these everblooming bush moss rose hybrids is that the foliage does not show as much tendency to mildew as the old mossed sorts.
Yet another possibility for rose exploration which has intrigued me for many years is the breeding of repeat (everblooming) flowering rambler type roses, with thin pliable canes, cluster flowering like the old 'Dorothy Perkins' but with tiny pointed hybrid tea shaped buds and miniature hybrid tea-like flowers. I have made a start in this direction but the project needs more time than I have had to devote to it.
For those readers who might wish more information on both my work with miniature roses and with the modern roses I suggest (a) my book All About Miniature Roses (1966) available from the author (in England contact David Austin Roses); (b) an article "A Study of Moss and Miniature Roses", published in the Creation Research Society Quarterly (January, 1967) and reprinted in the 1968 Annual of The American Rose Society.
Finally, readers may like to know about a bed in the National Rose Society's Trial Grounds at St. Albans. Six cvs of miniatures are entered in the trials and will be in their second year during 1969; they are: 'Lavender Lace', 'Gold Coin', 'Judy Fischer', 'Mary Adair', 'Little Mike', and Toy Clown'. These will no doubt soon be available commercially in Britain.


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