Volume 19

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Author: Wesley P. Hackett

PP: 57


One of the characteristics of the juvenile, non-flowering phase of Hedera helix is its striking ability to form adventitious roots on the stem of intact plants. In contrast, the adult flowering phase of this species does not form aerial adventitious roots and is difficult to root when leafy stem cuttings are placed under favorable environmental conditions (7). Many observations indicate that cuttings of most plants in the seedling (juvenile) state initiate roots more readily than in any other stage of development.

It has been known for many years that auxins stimulate adventitious root formation (13, 17). However, cuttings of many difficult-to-root plants, including the adult phase of Hedera helix, respond very little to auxin treatment (2, 9). There is evidence that endogenous factors, other than auxin, are important in the control of adventitious root initiation (4, 7, 8, 9). More specifically there is evidence that phenolic compounds such as catechol, pyrogallol, caffeic


Author: Wesley P. Hackett

PP: 105

It has been known for many years that individual lily bulb scales when separated from the mother bulb will form adventitious bulblets at their base when placed in favorable environmental conditions. Three to five bulblets will usually develop from each scale depending on the species and cultivar. This propagation technique is called "scaling" and is useful for rapid build up of stocks of a new cultivar or to establish pathogen-free planting stocks.

The objectives of the experiments reported in this paper were to find methods of producing bulblets under aseptic conditions and to increase the efficiency of bulblet production from scales. Accomplishment of these objectives would increase the commercial feasibility of multiplying and maintaining pathogen-free stocks and also increase the rate at which planting stocks of new cultivars could be built up.

In performing these experiments, bulb scales of Lilium longiflorum ‘Croft’ about 1.5 cm wide and 3.0 cm long were used. ‘Croft’ is a cultivar


Author: Hudson T. Hartmann

PP: 108

Some of our most ancient cultivated plants, as the fig, olive and grape, are ones that are readily propagated by hardwood cuttings. With these plants early man was able, when he turned to agricultural pursuits, to easily establish clones of superior types merely by inserting into the ground sticks broken from desirable seedlings, thereby producing great numbers of equally desirable plants.

Propagation by hardwood cuttings is, no doubt, the simplest and least expensive method of vegetative propagation. It would be most desirable to be able to extend this type of propagation to a much greater range of plants. It would be particularly desirable to be able to utilize hardwood cuttings in place of the more laborious layering methods now widely used in propagating clonal fruit tree rootstocks and other difficult to propagate plants. Furthermore, hardwood cutting propagation procedures lend themselves readily to mechanization practices which are more and more being utilized by the nursery


Author: Dale E. Kester

PP: 114

This report summarizes results of experiments carried out during the fall and winter, 1968–69, as part of a program to select clonal rootstocks for stone fruits (Prunus), with emphasis on peach × almond, F1 hybrids. Earlier, we found that cuttings of almond clones were impossible to root; peach was relatively easy-to-root and hybrids of peach and almond (P-A) were intermediate, with a range among clones from easy to difficult (3, 4). Hansen (1) has selected P-A clones that are nematode resistant and Hansen and Hartmann (2) reported good survival of hardwood cuttings of P-A clones if taken in the fall or early winter, treated with IBA and Captan, then planted directly into the nursery.

The purpose of the experiments reported here was to evaluate rooting of different Prunus clones. To do this we wanted to develop a screening procedure whereby we could accurately and easily evaluate the genetic ability of individual clones to initiate roots. We also wanted to distinguish "rooting


Author: Lee Rosenkranz

PP: 118

Initial work on rooting cuttings of Rhus cotinus ‘Royal Purple’, (red smoke tree), was started in the summer of 1965 with an attempt at rooting softwood cuttings taken at several intervals. This resulted in a complete failure, and a decision was made to look into the prospects of hardwood cuttings.

In the past all smoke trees had been propagated by grafting, but a shortage of understocks, and the tendency toward weak graft unions, prompted a consideration of rooting of cuttings.

In January, 1966, the first cuttings were stuck in pure sand in a heated greenhouse with a bench temperature of 70° to 72°F. One hundred cuttings were put in a regular cutting bench, and another 100 were placed under intermittent mist. All were terminal cuttings. Most cuttings leafed out, but those in the regular bench failed even to callus. Those under the mist lasted longer, and a few rooted, but the roots decayed before they were ready to dig.

In December, 1966, a cutting bed was built in an unheated poly


Author: Gottlob (Rudy) Wagner

PP: 119

Propagation by hardwood cuttings is known to be the least expensive and easiest way of reproducing plants vegetatively. The cuttings are easy to prepare and no special equipment is needed during the callusing and rooting period. Hardwood cuttings are made usually from one-year-old dormant wood. However, in propagating fruit rootstocks, one should follow the method best suited for his region. Factors to consider are:
  1. Source of the cutting material
  2. Timing — when is best to take cuttings
  3. Preparing the cuttings
  4. Treatment of the cuttings
  5. After-care of the cuttings

In 1960, Dr. Hudson Hartmann and Prof. Carl J. Hansen reported that ‘Old Home’ pear (Pyrus communis), is a valuable rootstocks in combating pear decline and fire blight. Cuttings can be rooted if taken in November with the bases soaked 24 hours in 200 ppm IBA, packed in moist, not wet, peat moss and placed at 65° to 70°F. These root in 3–4 weeks and can then be planted immediately in the nursery, weather permitting. If stored at 40°F., only 1/3


Author: J.P. Nitsch

PP: 123

Plant biologists have become convinced that each of the numerous cells which form a plant contain the complete genetic information necessary to reproduce a similar individual. Thus, if we could isolate a cell from either the root, the stem, or the leaf of that plant and find a way to make it grow, it would develop into a new plant exactly like the stock plant from which the cell had been isolated.

Author: R.L. Ticknor

PP: 132

Propagation of pines by cuttings has received comparatively little attention from horticulturists until recently (13,19,22) but has been the subject of intensive investigation by foresters at least as far back as 1934 (1). Most of the results reported in this review have been reported since O'Rourke's (19) article in the 1961 Proceedings. Much of the work has been done in non-English speaking countries so that I have had to depend on Forestry Abstracts for most of the results reported in this review. Each of the many factors which influence rooting will be discussed separately.

Tree age. Tree age is probably the most important factor in rooting pine cuttings. Watanabe (26) reported 4, 17 and 30 year Pinus densiflora rooted 62, 42 and 30% respectively. Kummerow (10), reporting on rooting needle bundle cuttings of P. radiata, found average rooting percentages for 1–3 year trees as 24.7%, for 7–9 year trees as 19.5%, and for 28 year trees as none. An even earlier loss of juvenile rooting


Author: Brian Gage

PP: 138

Our average annual quantity of plants grown from seed is 90,000. Twenty-five per cent of these are used as understock for our selected forms of magnolia, liquidambar, ginkgo, etc. A further 15% are California natives, the remaining being eucalyptus and miscellaneous trees and shrubs. We collect our own seeds where this is economically feasible, or when seed is not readily available, from commercial sources.

We keep accurate records of our seed collections, time of year, location, etc.; but, despite this information, it is interesting to note that each year our timing appears to be astray, and it is usually necessary to return to the site for further inspections of the new crop of seeds before collection. These extra trips usually prove fruitful, although in some cases very time-consuming, especially if we are collecting natives from high elevations, such as the huckleberry oak, Quercus vaccinifolium, or the pine mat manzanita, Arctostaphylos nevadensis. The current season at


Author: John C. Doty

PP: 141

We are all aware of certain plants which are difficult to transplant. In view of this, one can readily see the advantages of direct seeding into peat pots so as to reduce transplanting shock to a minimum.

Seeds selected for our tests were Arbutus menziesi (Pacific madrone), Mahonia nervosa (Cascade mahonia), and Cornus nuttallii (Pacific dogwood). It should be noted here that for the first two plants there is no problem if more than one seed were to germinate in a pot. Therefore, in the case of arbutus and mahonia, two to three seeds were used per container, but only one per pot for Cornus nuttallii.

Two types of containers were used: (1) 2½" × 3 1/3" peat pot filled with a standard potting mix, and (2) Jiffy "7's", which are basically a fertilized peat contained in a plastic net. Both the peat pots and the Jiffy "7's" were placed in standard 15 × 20 in. nursery flats to facilitate production seeding. An assembly line was set up on roller conveyers. Peat pots were filled at the potting bench,


Author: W.J. Curtis

PP: 142

Over the past years I have grown a few Acer palmatum seedlings with varying degree of success. Poor germination occurred sometimes but at other times germination was excellent; however other problems developed. I have sown the seed outside in beds, covered with sawdust, but always with a variable survival percentage. Some adverse problems are birds or mice in the beds; the mice ate the seeds or the pheasants picked off the seedlings as they came through the sawdust. On one occasion I was too late with shade on an April day when the temperature climbed to the high 80's. On another day I forgot to water when watering was critical.

Two years ago I changed procedures and have been following closely a more exact method of handling the seeds and seedlings of this plant. The seeds are picked as soon as they are pipe and spread out on newspapers in the greenhouse bench for a day or two. The wings rub off more easily with a little drying.

A standard flat is filled with a mixture of ½ peat and ½


Author: George F. Ryan

PP: 69

Etiolation results from the exclusion of light from plants or plant parts. In this discussion we are concerned only with the effect of excluding light from that portion of the stem from which roots may develop. Effects of light, or absence of light, on chlorophyll formation or other changes in the leaves are not a part of this discussion, because in the use of etiolation for propagation, leaves are allowed to develop normally in the light above the etiolated portion of the stem.

One of the externally visible effects on etiolated stems is blanching, resulting from the disappearance or lack of chlorophyll. Etiolation is sometimes defined in terms of this blanching effect, but in relation to propagation, the presence or absence of chlorophyll in the stem probably is of no significance.

Etiolation is generally thought of in relation to deliberate exclusion of light during stem development, or for a period of time prior to the rooting process, but exclusion of light in the normal procedure


Author: Richard Van Klaveren

PP: 144

Propagation of maples has always been considered a difficult task. Some maples, such as Acer platanoides and Acer saccharum, can be readily grown from seed, while others, such as Acer griseum, produce few fertile seeds, and these are difficult to germinate. Some maples, such as Acer saccharinum and Acer rubrum, produce seeds which will germinate soon after falling to the ground in midsummer, while seed of other species, such as Acer negundo and Acer triflorum, develop a hard seed coat which must be treated by scarification and they also need to be stratified. Most maples available in nurseries today have been grafted.

Only in recent years has the propagation of maples from softwood cuttings become practical. Two new techniques, the use of controlled mist and the availability of polyethylene plastics, have made this possible. The use of controlled mist in rooting softwood cuttings is not new, but its use on a widespread scale is. When a polyethylene cover is used, mist is unnecessary.


Author: Dara E. Emery

PP: 145

The Santa Barbara Botanic Garden is devoted exclusively to native California plants. The propagation unit at the garden consists of a small glass house, a lathhouse with a hotbed inside, and an intermittent mist unit with bottom heat located outside in nearly full sun. A modified U.C. mix is used for seed flats and pots. The canning soil, sterilized, is variable depending on what is obtainable. Cuttings, after being prepared are totally immersed in a malathion-Captan solution and, in most cases, the basal portion is dusted with Rootone. Because of our highly mineralized water, cuttings in the mist unit not rooted by 2½ to 3 months have very little chance of rooting and by 4 months are dumped. As soon as cuttings are rooted in the mist unit they are potted in plastic pots and placed in a hotbed with extra shade for two weeks to harden-off. The following eight native California species have presented propagation problems of one type or another.

Tree anemone, Carpenteria californica;


Author: J.H. Crossley

PP: 149

Within the last decade chemical growth retardants have opened a vast field for exploration in plant growth and flowering. The effects of these chemicals on ornamental plants have been widely reported, especially on rhododendrons, by Cathey (1, 2), Criley (3, 4), Leach (6), and Ticknor (7, 8), but there is very little information on the long-term residual effect of retardants on shoot growth, flowering or propagation of retardant-treated ornamentals. This prompted the author to make this study.

Author: Austin Kenyon

PP: 156

Our nursery has been providing winter protection for container-grown broadleaf evergreens since the winter of 1963. This was necessitated by severe damage and heavy losses during each of the three previous winters.

We are located in northeastern Oklahoma in the Cookson Hills approximately 50 miles west of Ft. Smith, Arkansas. The average minimum temperature is 5° to 10° F. below zero. However, overwintering in our area is further complicated by rapidly fluctuating temperatures, with highs in the 70° F. range sometimes being only 24 to 36 hours ahead of the extreme low temperatures. Therefore, most broadleaf evergreens grown in containers, such as pyracantha, euonymus, holly and the soft varieties of deciduous shrubs are subject to varying degrees of winter damage. We felt that polyethylene-covered houses offered the most promising solution, but several criteria had to be considered:

  1. The houses had to be low in cost.
  2. They had to be able to hold snow loads of 6 to 12 inches.
  3. They

Author: Henry B. Mollgaard

PP: 160

In a structure where three to six crops of potted plants are being transported during a year, provision for moving plants quickly and easily is essential. One effective means of operating a greenhouse efficiently is to mobilize equipment, using trucks, hand, and electric carts.

Easy accessibility around, to, and in the greenhouse must be provided for this equipment. Roads and walks inside and around the greenhouse should be either blacktop or concrete. The first is the least expensive, but gives some problems resulting from the weight of heavy equipment and from its softness during warm weather. The packing shed, too, should be completely surfaced.

Inside most new pot plant greenhouses the benches run crossways with a wide access aisle going the long way. As an example, a 37½ foot wide house may have a 5½ foot aisle and 32 foot long benches. The 5½ foot aisle provides enough space for an electric cart. Between the houses, a sheet of plastic is sometimes used to help control the


Author: Carl Zangger

PP: 162

Perry's Plants are growers of ground cover plants, mostly herbaceous types of perennials, and low-growing woody ornamental plants, as well as annual and perennial bedding plants. We produce several hundred thousand flats of these types of plants each year and are in production twelve months of the year.

All of our production is grown in standard southern California nursery flats, which are approximately 18 inches square and 3 inches deep. To us the unit of production is a flat, not a single plant. Most flats are planted 100 plants per flat although some have as few as 48 depending upon the plant and the specifications for a particular job

Almost all of the material we grow from cuttings or divisions are rooted and sold in the same flat without transplanting; seedlings are started in seed flats and transplanted Most varieties we grow are ready for sale in 30 to 90 days although a few slower growing types may take up to 120 days. Since most of these are grown quickly, it means that they


Author: A.R. Carter

PP: 172

This review will be in the form of a progress report.

GERMINATION OF SEEDS — About 350 B.C., Theophrastus reported that germination of rose seed was very slow and erratic so that, in order to avoid delay, cuttings were made. Some 450 years later, Pliny mentioned that rose seed germination was a very slow process. Here am I, about 2,300 years later, agreeing with both these learned gentlemen and one wonders just how slow progress can be!

The so-called "seed" found in rose hips is really a fruit and in many species, such as Rosa canina, such "seed" lies dormant for many months before germination takes place. If it were possible to control this dormancy, one would be nearer to being able to control the plant density in the field which, in turn, should lead to more uniform rootstock production.

Source of Seed — For the current work at Luddington Experimental Horticulture Station, homeproduced seed is being used. The seed from different bushes of wild R. canina is likely to behave differently,


Author: Brian E. Humphrey

PP: 180

Before production efficiency and rationalisation can take place, a number of basic factors to any business must be considered. Production must be related to the type of business in which the nurseryman is engaged; for example, the requirements of a retail company might be quite different than those of a wholesale company and a company engaged in both wholesale and retail trading would again vary from the previous two. The basic marketing techniques of garden centres and mail orders may profoundly influence the approach towards production. It is scarcely necessary for me to expand further upon these major factors.

Production for our retail trade is geared towards the propagation of a vast range of plants, generally in fairly small numbers, whereas the wholesale grower is normally engaged in the production of a fairly small range of plants in vast numbers. If the business is entirely orientated towards a garden centre, or more than one garden centre, or if it is a wholesale business


Author: A. Beryl Beakbane

PP: 192

A comparison of the anatomical structure of stems with their capacity to form adventitious roots has shown that a relationship exists between anatomy and rooting capacity in a wide range of species (1, 2, 4, 5, 6, 7, 8). In considering structure as it may affect rooting, it is important to have a clear, visual image of the location of the tissues that are chiefly concerned. They occur near to the outside of stems and include cork, cortex, and phloem. A sclerenchymatous sheath derived from the primary phloem is, for example, often present in plants that are difficult to root from cuttings (Fig. 1-above) and it may provide a physiological barrier to the initiation of roots, or a mechanical barrier to their emergence (1, 4). In contrast, only scattered groups of fibres (Fig. 1— below) are present in this zone in many free-rooting plants. In stems from shy— and free-rooting clones of pome fruits viewed at a higher magnification one can discern both individual fibre elements and

Author: R.J. Garner

PP: 202

Dead plants cannot be propagated. Most of us accept this truth but we do not always behave as though we really believe it. Life being essential we should endeavor to maintain it.

Propagators spend much time ‘multiplying by division’, often into quite small pieces of parts of shoot, root or leaves, which they then place in situations where they grow to wholeness once again. There are many hazards in these processes and the greatest of these is desiccation or drying which, carried too far, is certain death. Herbaceous leafy cuttings are the chief sufferers but root cuttings are in the same danger, though the damage may not be immediately obvious. There is a tendency today to rely upon recovery under mist, but a wise man takes reasonable precautions. Moist-lined containers should be used for the collection of vulnerable cuttings. Polyethylene is suitable provided it is completely shaded whilst in use. Very full polybags may lead to suffocation of active cuttings; partial filling and


Author: A.N. Roberts

PP: 77

We were impressed with a statement made several years ago by Dr. Vernon T. Stoutemyer of the University of California at Los Angeles, to the effect that possibly the reason cutting propagation research has remained quite primitive is that we have not solved the problem of timing to the extent that we can duplicate an experiment from one year to the next. We have taken this comment rather seriously, because we respect the research done by this worker over the years, and his conclusion matches precisely our own.

With the help of several graduate students, we have been attempting to establish a morphological time scale for predicting rooting potential in certain woody species, and to correlate physiological condition and developmental events with shoot rootability (1, 3). We have had some success, and have changed many of our ideas, but much remains to be done. In the beginning, it was our concept that seasonal changes in shoot rootability were associated with tissue and physiological


Author: A.D. Weguelin

PP: 204

We have successfully constructed plastic covered shelters at our nursery using, principally, second-hand units from ex-Service Nissen Huts and wooden railway sleepers (ties).

The structure is built on the railway sleepers placed in two lines 17 feet apart, outside measurement. The curved Nissen hut irons, consisting of two 10-foot lengths, and one quarter-length of 2 feet, 6 inches, are welded together to form one arc of 22 feet, 6 inches. The angles on the irons are used to bolt to the sleepers with coach bolts.

These iron "ribs" are 6 feet apart and distance pieces of six-foot lengths of 2-inch by 1-inch timber keep them at this distance. Wires (10 gauge) are run the length of the house, threaded through the holes which are already in the centre of the irons. In the end irons an eye-bolt is used to strain the wire taut.

Nylon net is then stretched over the frames and secured to the sleepers by staples at the sides and ends. The plastic is then stretched over the frames and held down


Author: G.P. Chandler

PP: 205

For this purpose I have split Daphnes, into three groups:

Group 1. In this group I include the following species — Daphne collina, D. × hybrida, D. odora and its varieties, D. retusa, and D. tangutica.

The time for taking these cuttings is late July to the end of August but the all-important factor lies in taking them when they have reached the right degree of maturity. The cuttings should be of current season's growth. The length of cuttings should not be more than 3-inches but can be smaller according to the growth of respective species; cuttings may be a joint or a heel as long as the cutting taken does not exceed 3 inches. With joint cuttings it is a good tip to split them about ¼ inch at the base across the bud. This helps to form a good callus.

The cuttings are inserted into a mixture of 2-parts sharp sand and 1-part Irish peat moss. Pans or cutting trays may be used, with coarse chippings for drainage. After filling the tray with the cutting mixture, ¼ in. layer of sand is put


Author: Stephen Haines

PP: 206

I suppose that it must be the variation in leaf color that attracts me and many others to the Acer platanoides and A. pseudoplatanus varieties. Nothing is more satisfying than a good stand of ‘Goldsworth Purple’ contrasting with ‘Drummondii’ or ‘Worleei’ and of course there is no difficulty in selling them.

In common with many other growers, we have experienced great difficulty in obtaining a crop of these plants from buds. I can claim nothing original in the method now adopted which over the last few years has given us excellent crops. It is based on a study of successful growers' methods and of the growth pattern of the Acer species in question.

Our first requirement is a young rootstock with a fibrous root system. A two-year transplanted seedling, 8 – 10 mm size seems ideal; anything larger is usually coarse-barked at the level of bud insertion. These rootstocks should be cut back to 18 inches and planted in well-manured ground; it is essential that the stock grow vigorously throughout the


Author: James C. Kelly

PP: 208

Studies on production of hybrid rhododendrons from stem cuttings commenced at Kinsealy in 1968. On October 30th cuttings were taken from four-year-old stock plants of Dutch origin. These cuttings were from four to six inches long, and taken as far as possible from the underside of the plants. In preparation, only four leaves were left on the cuttings, which were wounded heavily on both sides at their base and treated with a proprietary hormone powder (0.8% IBA). The cuttings were then inserted in a rooting medium of two parts peatmoss and one part washed river sand, then placed under mist. The bottom temperature was 70–75°F. As controls, small numbers of cuttings of the cultivars used in the trial were left unwounded or received no hormone treatment.

There was no advantage in re-inserting cuttings after the initial lifting, as very few additional cuttings rooted, whilst the remainder quickly degraded. The new plantlets were then potted into four-inch clay pots in a pure peatmoss


Author: J.M. Anstey

PP: 211

It seems ironical to me that such an acknowledged expert as Jim Wells can write a book in which he deals with a subject such as this and then you ask me to stand up and speak on the subject. Nevertheless, such is human nature that we had taken cuttings of Acer palmatum ‘Atropurpureum’ two years running before I thought of seeing what the experts had to say! Most of what I am going to say now concerns the difference between muddling through in our own way and learning from other people's mistakes.

Early in 1968 it was decided that we should try Acer palmatum ‘Atropurpureum’ from cuttings. Thirty-three stock plants were therefore taken under glass in February, bedded in a frame filled with peat and given regular doses of liquid feed throughout the growing season. The temperature was kept at a minimum of 45°F and, at the beginning of April, the first batch of cuttings were taken when the shoots were long enough and one pair of leaves had fully expanded. Cuttings were then taken at intervals


Author: Peter Dummer

PP: 213

Over the past few years there has been an ever-increasing demand for large quantities of trees and shrubs and, as a result, we have had to change some of our methods of raising stock from seed.

Various reports, such as those of the I.P.P.S., and the Woody Plant Seed Manual (published by the Forestry Service of the U. S. Department of Agriculture) have been found particularly useful. This latter book is notable for its detailed work on the treatment of seeds with sulphuric acid. A visit a few years ago to the Forestry Commission Nursery at West Moors, near Ringwood in Hampshire, also provided us with ideas on different seed-raising techniques. These changed practices have increased the quality of the seedlings we have raised and reduced our production costs.


Author: D.M. Donovan

PP: 216

The management of a nursery cannot be entirely separated in function from the propagator or other staff, as their interest is common, namely the production of plants or seeds of economic or ornamental merit for sale — albeit the one for profit and the other for livelihood. The management alone initially determines the type of enterprise to be capitalised although many influences in the course of time will alter the original concept, not least the advice of the propagation staff.

The present business of F. Toynbee, Ltd., comprises a wide and complex pattern of wholesale trade despatch, contract supply, landscaping and retail sales. The choice of plants grown here is partly determined by the advice of the propagator.

The management must decide wheather to grow an increasing number of different kinds of plants or reduce to a few hundred which have a guaranteed minimal annual sale. Whichever choice is made, an estimate of plant quantities is required, close to actual sales, and an


Author: J.K. Hulme

PP: 218

There are many snags in propagating alpine plants. Some of the high mountain species of Androsace, which produce tight rosettes of minute leaves, can only be raised from seed which is rarely produced in quantity and the seedlings grow very slowly.

Raising plants from seed is of considerable importance to the propagator of alpine plants who must be prepared to meet a range of spcialised requirements. Primula whitei, P. edgeworthii and P. gracilipes and their relatives of the Petiolaris section produce seeds which rapidly lose their viability. They must be sown as soon as they are ripe, with the seeds taken directly from capsule to seed-pan. Some people, however, have been led to the mistaken conclusion that all species of Primula should be so treated. In fact, the greater number of species respond far better to a spring-sowing programme; in this way they grow and develop and are ready to enter the normal resting period when winter arrives.

The seeds of Gentiana verna and Lewisia


Author: D. Staton

PP: 219


Preparation for the grafting of miniature rose trees starts at the beginning of November. The second-grade miniature rose trees are pruned fairly hard, potted up into four-inch ‘long toms’ and placed into a cold frame or glasshouse where they are given a cold period for about four weeks.

The grafting pit is prepared in early December with about 9 inches of peat. We like to get the peat at a temperature of 80°F, with an air temperature of 72°F. The peat is watered to keep the inside of the grafting pit humid, care being taken to ensure that the peat is not so wet that excess water can be squeezed out by pressure. Air and soil thermometers should be placed in a convenient position in the pit in order to keep a regular check on temperature. Two Dutch lights, one on top of the other, are placed the length of the grafting pit in order that the condensation particles which form on the glass are smaller thus preventing too much water from falling on the grafts. In mid-December the


Author: D. Knuckey

PP: 221

The idea of propagating magnolias by bud-grafting stemmed from five main sources:
  1. Mr. Neil Treseder had started research on a comprehensive book on "Temperate Magnolias and Their Hybrids", and had commissioned an artist to paint a set of the best forms to use as illustrations.
  2. We knew that a few grafted plants of selected clones of Asiatic magnolias existed, and that these had reached flowering maturity considerably sooner than seedling plants of the same type (e.g. Magnolia campbellii subsp. mollicomata convar. williamsiana ‘Lanarth’.
  3. Mr. Treseder anticipated that the coloured illustrations in his book would stimulate a world-wide demand for plants of selected clones.
  4. Early in 1967 Mr. Treseder carried out investigations into the propagation of magnolias by bud-grafting, including methods used in America and Japan. He learned that Japanese nurserymen were achieving considerable success by direct budding onto two-year M. kobus seedlings in open field conditions whilst still in

Author: Bruce Usrey

PP: 82

In 1964 Monrovia Nursery designed and built a controlled environment greenhouse. This plastic house was designed to provide the best possible environment with the least operating and maintenance cost. Along with this was the hope of increasing rooting percentages and decreasing the amount of labor used in airing, watering, and shading the hot frames.

In designing this house a number of problems had to be solved. These were:

  1. Control of humidity
  2. Efficient heating
  3. Control of air temperature
  4. High light with minimum heat
  5. Low maintenance cost

First, atmospheric humidity is electronically controlled by use of an Hygrodynamics, Inc. humistat. This humistat is extremely sensitive in the range of 70% to 97% humidity while being almost maintenance free. This humistat is tied into the hydraulic and pneumatic mist systems by relays and solenoids and operates either, or both, as needed. The hydraulic system is under the bench and is capable of maintaining a humidity of 80%, when used by itself. The nozzles are Flora Mist and spaced 4 by 8 with an operating pressure of 90 pounds. This system uses 75,000 gallons of domestic water per day


Author: Peter Hutchinson

PP: 223

Bins in the past have generally been associated with the propagation of fruit tree rootstocks. From simple beginnings in the early 1950's, when they were just utilized for storage, uses for them in rooting hardwood cuttings have developed, with the inclusion of soil warming procedures. Firstly, temperatures of 45° – 50°F were used, but more recently 70°F appears to be the optimum, especially for apple rootstocks.

Why use bins?

  1. To increase the number of field liners over that which can be obtained from using more traditional methods such as hardwood cuttings in the open or in cold frames, e.g. Cotoneaster × watereri.
  2. To propagate ornamental plants closely related to fruit tree rootstocks, e.g. Prunus cerasifera ‘Nigra’, Malus ‘Profusion’.
  3. To propagate ornamental plants not normally propagated by hardwood cuttings, e.g. Crataegus ‘Paul's Scarlet’, for use as a hedging plant. By simplifying, the cost of production can be reduced.

Siting. Ideally the bins should be placed on the north side of


Author: R.D. Anderson

PP: 227

We are wholesale producers of container-grown plants and our object is to produce a plant which is well-grown and well-rooted in the container, attractive to the eye and easily transportable, as we feel a plant of this kind is best suited for self-service garden centre sale. These points need not apply to material produced for landscape work where larger plants are required.

There are two methods of producing a plant in a container:—

  1. Container-grown. Plants are grown in containers throughout their life.
  2. Field-grown then containerised. One-year liners or older plants are lifted from the field and potted into containers.

In order to achieve our objectives we use the "container-grown" method to produce all our plants, with the exception of trees and roses which, because of their method of propagation, do not fit easily into this system.

We chose this system for the following reasons:

  1. We have more control over plant growth, which in turn leads to a more uniform product.
  2. The

Author: Thomas C. Thursfield

PP: 229

With the introduction of modern herbicides and machinery is there more time to spare when the spring planting is over? On our nursery we have no mechanisation at all as the soil is moist, peaty and light, with no stones at all. We plant everything in beds by hand as you will see on the film and we crop the ground heavily. After shrub planting, as we have no container trade we decided to increase and extend our selling time by producing about 250 to 300 thousand spring and summer flowering border and herbaceous plants. We sell these on our two outdoor market stalls in local towns in the industrial Potteries area, which is a mainstay of our existence.

We operate our nursery as three small units. The smallest, operated by my father and two women part-time workers, produces from seed as many plants as possible in boxes of 60, for transplanting on to spare beds in the nursery. As we use farmyard manure regularly we find this good preparation for rotation of shrub planting.

The second unit



PP: 230

FRANK WILLARD: Can I have comments from members on the quality of hardy hybrid rhododendrons when grown on their own roots? I understand that a well-known Dutch nursery has given up growing varieties of the ‘Pink Pearl’ type from cuttings because, though they root satisfactorily, they do not ball-up as well as grafted plants.

Author: IR B.C.M. Van Elk

PP: 232

The propagation of conifers by cuttings in Boskoop differs a little from the methods used elsewhere in the world, though this does not mean that part of the research cannot be modified for use in other areas. It is rather difficult to translate the results gained in a cold double frame outside to a glass-house, with or without mist equipment.

Cutting material used in England is quite different from ours. In Boskoop we usually take weak-growing side tips of young plants in full growth. It must be remembered that in Boskoop we have to send you small plants because of import taxes, transport costs, etc; so we have to take our cuttings from young plants, whilst you, perhaps, may take them from larger plants which we do not have.

Conifer cuttings are taken during autumn which, as I shall subsequently show you, is usually the best time. So far as I know the selection of the right time is largely by trial and error and with the art of "green fingers". The Adivsory Service takes it for granted


Author: A.B. Macdonald

PP: 241

Searching through the literature, one finds that a considerable amount of research and experimentation has been carried out relative to this subject, particularly in the United States, U.S.S.R. and some European countries. Lighting has three main roles. These are —
  1. Rooting of cuttings. This can be subdivided into —
    1. treatment of the stock plant;
    2. application to the cutting in the actual rooting bench.
  2. Establishment of rooted cuttings. This can be interpreted as the continuation of growth to delay or prevent dormancy, with the aim of reducing losses of specific deciduous subjects during the winter.
  3. Breeding. To speed up a breeding programme when plant breeders are anxious to see the results of their crosses earlier, e.g. Rhododendron, which has flowered after 3 years, instead of 6 years. It may be practical with some subjects to cause plants of early and late varieties to bloom simultaneously so that they can be hybridized.

I have purposely used the term "lighting" in this paper, as supplementary


Author: P.D.A. McMillan Browse

PP: 247

The teaching of plant propagation by any one person is, in essence, a personal philosophy of that particular individual, developed as a result of his experience in that field. It may well differ radically from the views of other teachers but I offer no apologies for this — my own approach. Basically this philosophy is a synthesis of three components. Firstly, there is the influence of one's original teachers who must necessarily have the major effect for they are able to mould one's thinking; this component is thus the most telling as it is, perhaps, the most difficult to disregard. Secondly, the effect of the work and thinking of other teachers, researchers and practical propagators must have marked influences in developing one's approach and, in the connection, I owe something to almost everyone to whom I have talked or with whom I have worked. Finally, it is one's own ideas and thinking in rationalizing all the information and knowledge of the previous components that provides a final

Author: Unknown

PP: 249

A party of 34 members (including a few guests) flew from Coventry airport to Rotterdam and thence went by coach to Boskoop where they spent 7 packed hours. The arrangements went like clockwork and not even the fact that the weather was bleak and wet throughout damped the enthusiasm of anyone; it was voted an excellent and most informative visit, a great value for the money and the officers of I.P.P.S. were encouraged to consider further possible short visits abroad.

The party visited the Research Station at Boskoop where they were greeted by the new Director, Dr. Roelofsen, himself an I.P.P.S. member. After an excellent ‘koffietafel’ at the Hotel Florida, four nurseries were visited —
          Fa Th. Streng and Fa J. Streng (2 nurseries)
          Fa G. Kooy and Zn.
          Fa F. J. Grootendorst and Zn.


Author: Bruce A. Briggs

PP: 275

I shall illustrate with slides some of the types of applied research which we as nurserymen can carry out in the course of our daily business. For those who are not in attendance at this meeting, a description of these projects will make up this article.

I feel that in order to upgrade the industry, basic research from institutions all over the world must be translated into applied research within the institutions and within the industry. A free exchange of information in detail amongst teacher and students, research scientists, and members of the industry is very important. A seemingly insignificant detail found in research may prove to be the missing link which may bring success to a practical plantsman. Or close daily observation in the field can bring to light valuable insights to be pursued further by the scientist or student.

The industry needs to cut down the lapse of time between research and practical application in the nursery. Organizations such as our International Plant


Author: James D. Murphy Jr, J.B. Gartner, M.M. Meyer

PP: 279

The vegetative propagation of ornamental plants presents many problems. Some problems result from the number of times cuttings must be handled. They must be taken, made up, and stuck into a rooting medium. After the cuttings have rooted, they must then be removed from the rooting medium, potted into a growing medium or packed for shipping. This process requires several handling steps which results in high labor costs. When cuttings are removed from the medium, roots have a tendency to become desiccated and break. This delays establishment of the cutting.

These problems may be overcome by using small units or pots filled with a propagating medium in which cuttings can be rooted, grown, or shipped without removal from the rooting medium. This process saves labor the cuttings may grow better than those removed from the rooting medium because chances for root desiccation, breakage, and infection are reduced. Several individual, direct-rooting media have been developed for use with


Author: Gottlob (Rudy) Wagner

PP: 85

Propagating under continuous mist has limited use and depends upon the plants and type of cutting to be propagated. The location is also very important to consider as it is most useful in outdoor propagation.

We are using continuous mist for summer propagation of ornamental broadleaf evergreen and deciduous stock. We also propagate some fruit rootstocks by softwood cuttings under continuous mist: Prunus besseyi, P. tomentosa and some other plum rootstocks. One must be selective as there are a few species that do not tolerate continuous mist. Since our mother stock block is near our lathhouse, we moved our propagating benches right into the lathhouse to avoid drifting mist and to provide some shade from the hot sun. The benches are 30 inches off the ground, four feet wide with eight inch sides. The water is brought in through a one-inch line that runs along the base of the bench's front side with a ¾ inch outlet every four feet. This gives every four square feet of bench space an


Author: Alfred J. Fordham

PP: 284

Physiological juvenility in plants has long been recognized and much has been published concerning it. Through the years a number of articles have appeared in the Proceedings of this society describing juvenility and its importance to the plant propagator.

When plants are grown from seeds, characteristics which appear on the young seedlings often differ greatly from those which are found later in the plant's life. In the case of pines, the first or juvenile shoots are gradually replaced by mature growth. This slide showing seedlings of Pinus canariensis illustrates the transition from the juvenile to the mature stage. The presence of juvenility at the lower portions of the plants is indicated by pliable stems bearing solitary leaves which are bluish-green in color and are of soft texture. Evidence of maturity is manifested in the upper portions by leaves that are borne in bundles of three, are grassy-green and of firm texture. The interval between the advent of maturity and time of


Author: Vincent K. Bailey

PP: 287

I should like to introduce the subject, "Outdoor Softwood Cutting Propagation", with a discussion of the need for something other than the conventional method in the greenhouse although your results, and ours at Bailey's, have been very satisfactory with various types of mist.

The past 15 or 18 years have produced many variations of the use of mist propagation systems. Many of you here have heard a number of them described and no doubt have used one or more of them. We, at Bailey's, are very happy with a circular bed. My nephew, Rodney Bailey, discussed this with you two years ago. We are even more sold on the system now.

All of us are familiar with the fine stands obtained with many varieties when greenhouses are used. You are all familiar with the cost of building a greenhouse as well as the rather high maintenance cost. We need a reason for considering going to any other method. The reason we at Bailey's have adopted the outdoor method is purely a matter of economics. We are producing a


Author: Lawrence L. Carville

PP: 290

Propagation by softwood cuttings under poly tents is not a new technique but it is a topic which merits periodic review by this Society. Over the years, as experimentation gives way to new methods, and as improvements are made to accepted techniques, we have a responsibility to the membership of our Society to spread the Gospel and share in the wealth of new knowledge.

The method currently being used by The Rhode Island Nurseries was developed and perfected by a valued friend of mine: my predecessor and the Dean of American Propagators, Mr. Martin Van Hof. Previous references to this subject can be found in papers by Mr. Roger Coggeshall in the 1953 edition of the Proceedings and by Mr. A. R. Buckley in the 1955 edition of the Proceedings. Mr. Van Hof began his experimentation with this method in the early 1950's and it has been perfected over the years. In my brief association with The Rhode Island Nurseries I have found this method to be extremely simple and at the same time highly


Author: Peter Orum

PP: 294

Cold-frame propagation of ornamental woody plants has always been an accepted method. It has worked poorly and it has worked well, but seldom has it been very practical.

I once visited a large nursery in Germany. It was said to have several thousand glass-sashes in its propagation area. The amount of people needed to take care of this and carry sashes around ran almost into the hundreds.

Some years ago my close associate, John Wilde, and I started out with the goal of developing a practical system for propagation in outdoor frames. Our three main premises were: (1) it had to be well adapted to the ornamentals we desired to grow; (2) it had to be economical; and (3) it had to be suited for large scale production. Through modification of methods used by other propagators and some new developments of our own we have come a long way toward this goal.

To paint the clearest picture for you, I have divided my subject into three subgroups:

  1. Frame Construction
  2. Propagation in the Frame
  3. Adaptability



Author: M.M. Meyer Jr

PP: 300

The exact response of woody ornamental plants to fertilizer applications is often difficult to measure. This is because of the nature of the growth of these plants. The growth to be considered here and of concern to ornamental horticulturists is shoot growth or, specifically, growth of terminal meristems of the shoots of woody plants. This growth controls the form of the plant, produces leaves and flowers, and gives interest and environmental modification to the landscape. The nature of this shoot growth and response of this growth to fertilizer applications at various times will be considered.

What is the nature of growth of woody plants in temperate regions? Woody plants break buds and initiate growth from preformed parts in the spring. This may constitute the total height growth for the season in some plants; however, in other plants it may not. The growth of woody plants can be divided into two basic patterns. The first of these patterns can be referred to as homophyllous which


Author: Robert L. Ticknor

PP: 305

Phosphorus used in larger amounts than normal has been reported by McGuire (4), Myhre and Mortensen (5), Ryan (6) and Vanderbilt (9) to increase flower bud set in rhododendrons. This is particularly true for two— and three-year-old plants which, in some varieties, are difficult to bud.

Growth regulating chemicals also have been suggested as a means of increasing flowering of rhododendrons by Cathey and Taylor (1), Criley and Mastalerz (2), Crossley (3) and Ticknor (7) and Ticknor and Nance (8). Most of this work was done under greenhouse, conditions, although the variety ‘Roseum Elegans’ growing in the field was used in some previous trials.

To test the relative merits of these two systems of increasing flowering of field-grown rhododendrons under Willamette Valley conditions, a trial was started in 1968. Five varieties— ‘Elizabeth Hobbie’, ‘Princess Juliana’, ‘Pink Pearl’, ‘Roseum Elegans" and ‘White Pearl’—known to vary in ease of budding were planted June 19, 1968. One month prior to


Author: Andrew N. Adams Jr

PP: 309

For those of us who grow azaleas of the evergreen types, Kurume, Glenn Dale, Gable, Kaempferi and their hybrids, it is certainly discouraging every spring to find so many plants that are not saleable due to either bark split or bud damage. Most azalea damage, we have found over the years, occurs around the middle of October or the first part of November, after a long Indian summer with lush growing conditions — no frost, just warm rains. The growing season generally ends the first night with the temperature dropping to 23°F or so.

We have often said, and I know many of you folks have too, if we could only stop this growth the latter part of August or early September and be satisfied, instead of pushing our plants right up until the last good fall day. One method, which is time proven, of course, is to dig every plant around the middle of August and check its growth, but that went out with the depression when labor wages started skyrocketing.


Author: G. Tehrani, D.A. Logan

PP: 314


Clonal propagation of some plum rootstocks by hardwood cuttings is more economical and less time consuming under English conditions than the conventional stooling and layering techniques (2, 4, 7). Garner (7) rooted plum rootstocks by collecting hardwood cuttings in the fall and storing them in insulated bins for the winter months at a basal temperature of 45°F. The cuttings were budded in the first growing season and produced satisfactory trees.

In Ontario, imported Myrobalan plum seedlings have been widely used as plum rootstocks. They were quite variable in vigor and there was no assurance that they were virus-free. Interest in propagating plum rootstocks in Canada has been increased by a recent embargo on the importation of nursery stock from Europe. The present investigation was undertaken to study the feasibility of clonal propagation of different plum and peach rootstocks under Ontario conditions.


Author: P. Fiorino, J.N. Cummins, J. Gilpatrick

PP: 320


Decreasing damage caused by fungi and other microorganisms is among the principal means of improving methods of propagating woody plants by cuttings. Softwood cuttings under mist or in propagation boxes provide particularly favorable conditions for the growth and spread of fungus diseases. To produce important economic benefits, a fungicidal treatment should meet three conditions: (1) the treatment must appreciably reduce the incidence of disease; (2) the treatment must not be harmful to the plant material being propagated; and (3) the treatment must not interfere with the rooting/establishment process.

Under intermittent mist, cuttings of many species of Prunus are susceptible to Botrytis cinerea and a number of other pathogens. Selection and utilization of asexually propagated rootstocks for peach, plum, apricot and sweet and sour cherries depends in part on development of disease control systems.

Three types of damage by fungi may be distinguished on many lots of Prunus


Author: Robert E. Farmer Jr, Geraldine C. Hall

PP: 330

Vegetative propagation of black cherry (Prunus serotina Ehrhart) is essential to currently expanding breeding programs designed to produce forest tree stock with genetic potential for superior growth rate, form, and pest resistance. At present, grafting is being used successfully to establish breeding arboretums of phenotypically superior selections from natural populations, the first step in breeding. It would be more desirable, however, to use rooted cuttings in this work in order to circumvent possible stock-scion problems. In this high-value species, genetically improved clonal stock might also be produced commercially via cuttings. Thus, methods of rooting cuttings are of considerable potential value. Mist propagation techniques have been developed for named varieties and clonal rootstocks of horticulturally useful cherries (2, 3, 4). However, we found no report of black cherry rooting in the literature, although Cech2 has rooted cuttings taken from stump sprouts of mature

Author: Ron Klupenger

PP: 86

There have been many problems in cold storage of nursery material in the past, such as plants drying out, plants left in the cooler too long without lights, etc.

I think that misting has helped in solving some of these problems. It eliminates dehydration and drying-out of plants. With misting you don't have to be "Johnny on the Spot" with watering. There has been a great deal of loss without humidity control. We have experienced this over a number of years in precooling azaleas. It was all due to lack of knowledge of misting in cold storage.

Our first experience with misting came a few years ago when we had to rent cooler space and there were humidifiers in them. We were using the coolers for summer chilling, giving the azaleas six weeks of cold storage to produce late September and early October bloom. After the plants were in these coolers for six weeks, we could tell the difference in forcing. They came out with more lush foliage and seemed to react better to forcing. Also, we didn't


Author: Sidney Waxman

PP: 338


I'm sure most of you know what a witches' broom is, but for the benefit of those who are in the dark, I'll first try to describe what witches' brooms are and why they hold such fascination to those of us who are collecting and experimenting with them.

A witches' broom is an abnormal shrub-like growth that occurs only occasionally on various species of woody plants. Most often, it occupies only a small part of the tree while the remainder consists of normal leaves and branches. The broom is considered abnormal because its structure usually differs quite sharply from that of the normal part of the tree. The development of the broom is not the result of a gradual change in structure, but is abrupt, and its point of origin is easily identified (Fig. 1).

I prefer to categorize brooms into two groups; 1) those that are caused by parasitic agents, such as dwarf mistletoe,


Author: Alfred J. Fordham

PP: 346

Acer griseum, the paper bark maple, is a striking small tree with unique characteristics which lead to interest at all seasons of the year. In spring its newly developing trifoliate leaves are red-orange and when fully expanded they become green on their upper surfaces and conspicuously grey-green beneath. This greyish aspect is indicated by the specific name, griseum. In autumn its brilliant foliage is tinted from yellow through orange to deep red. Its outstanding feature, however, is dark reddish-orange bark whose outer layer peels away revealing orange bark beneath, which then darkens to resemble burnished bronze. During winter, when contrasted against snow, or when wetted by rain, the color of its bark is emphasized and A. griseum becomes truly magnificent.

This small tree has great popular appeal and many people are anxious to acquire it. However, owing to propagational difficulties, it has remained rare through the years and demand has exceeded supply.

Acer griseum was introduced


Author: Joerg Leiss

PP: 349

Hamamelis or Witch-Hazels, as a group of plants, are probably known to most of you but are propagated and sold by only a few. I think that the unusual characteristics, such as the flowering period, fall and winter to early spring, warrant a much larger quantity to be propagated than there is now. The yellow, orange, and ruby, lacy flowers brighten an otherwise bleak winter scene, when no shrub shows any sign of life.

Author: Knox M. Henry

PP: 353

Mr. President, fellow members, guests: I find it difficult to express my disappointment at not being able to be with you in person today. The presence at the meeting of many of my fellow Canadians will attest to the fact that Canada is not so cold that I am frozen and thus unable to move. We moved our entire business to a new location during the past ten months, yet up until last Friday I had expected to be with you. I hope the taping of my talk will prove acceptable to you.

Our firm began as a market garden operation owned by the late Mr. Frank Reeves. Starting on the recently vacated premises in 1923 the business evolved from a position of solely growing vegetables to include a floriculture crop of chrysanthemums, snapdragons, etc. After Ken Reeves returned from the European theatre after World War II, he worked for a couple of years with his uncle, the late Cecil Delworth. Doubtless the experience he gained during his time with ‘Uncle Cec’ had a definite effect upon the future course


Author: John J. McGuire

PP: 357

Container plant production has been increasing in the Northeast for the past ten years. It has not yet developed to the levels found in the South or Far West but the rate of increase indicates it may one day be a major form of plant production in the Northeast. Growers in this area have been faced with problems not encountered in the milder climates. Specifically, the relatively short summer season requires a very efficient production program. This, and overwintering problems, have been the major reasons for slower development of this method of plant production in New England.

Most growers have now overcome the problem of overwiner storage by use of Quonset poly-houses. These houses are constructed over the plants in the growing areas, eliminating or reducing labor costs for moving plants. To make use of the short growing season, growers have also met the challenge by developing an efficient growing program. This parallels the year-round problems of the commercial florist. His problems are very much like those of the container grower. He is limited to growing his crops


Author: Earl H. Robinson

PP: 360

I would like to speak to you on mechanization at our nursery in five main categories: 1) Propagation, 2) Greenhouse Growing, 3) Field Growing, 4) Over-wintering and 5) Shipping.

Author: Richard W. Bosley

PP: 363

My paper will probably be one of the shortest ever given but I feel the message it contains can be very important to you.

At the Bosley Nursery we have been propagating a similar line of plant material under mist with the same water source for a number of years. We have never had as high a rooting percentage as others in this Society profess to achieve but then we didn't always tend to believe some of the figures we heard. In the 1968 summer and fall propagation season our results were even worse and it prompted us to have the mist water checked for agricultural suitability. We found the total soluble salt content to be moderately high for mist propagation of azaleas and rhododendrons. What was even more damaging was that the concentrations of both sodium and chloride were high for these sensitive crops.

The choice became: 1) find a new source of a better quality water; 2) install de-mineralizing equipment; or 3) stop growing those crops. We chose to install city water which is of much


Author: David Wildung, Harold Pellett

PP: 364


Even though the art of graftage has been known and used in plant propagation for centuries relatively little is known about stock-scion relationships. There has been quite a bit of work done to study the influence of rootstock on plant growth and some on nutrition but very little work has been done to study the influence of rootstock-scion interactions as they might affect hardiness.

The rootstock could affect scion hardiness in one of several ways. Hardy rootstocks might induce hardier scions strictly through their use. The root system of certain rootstocks may have the ability to survive or escape root injury where other rootstocks cannot. In studies at Minnesota we have found that there is quite a range in hardiness capabilities of the various Malling and Malling-Merton stocks. Other workers have reported similar results (1, 2). Certain rootstocks may, due to earlier maturity or later bud-break, enable a scion variety to escape early and late winter injury by hardening


Author: Elwin R. Orton Jr

PP: 371

The development of new and superior cultivars is the primary objective of the breeding program with woody ornamentals at Rutgers University — The State University of New Jersey. For the most part, the improvements sought are increased winter hardiness, increased resistance to insect pests, and improved foliage and fruiting characteristics and, in some cases, decreased plant size. Work is also being devoted to the development of plants that exhibit characteristics quite novel for the plant material in question.

The plant species currently receiving most attention in the breeding program belong to the genera Ilex and Cornus. The starting point of the breeding project with each species has been the initiation and maintenance of a cultivar performance trials. Such trials are important as they make it possible to evaluate plants of the currently available cultivars under reasonably uniform conditions at one planting site and, thus, to assess the variability present within the cultivated plants


Author: J.C. McDaniel, Sara D. Groves

PP: 376

Seedlings grown as Magnolia grandiflora are a variable complex. In the opinion of the first author, this variation is, so far as horticulturally superior forms are concerned, in large part associated with long-continued introgression of M. grandiflora by M. virginiana australis in areas of the southern U. S. coastal plains where their ranges overlap. A high proportion of the new and old select cultivars of M. grandiflora, including the ‘Exmouth’ which has been propagated for 230 years, have characteristics, particularly in their foliage, resembling those of indisputable hybrids such as ‘Freeman’ and others bred since 1930.

The distinctive clone now offered as ‘Griffin’ is believed to be the result of chance hybridization. It is probably a later-generation hybrid, which appears to be fully fertile, unlike the known F1. hybrids between diploid M. virginiana and hexaploid M. grandiflora, which are often highly sterile.

The original ‘Griffin’ plant, in a city park at Griffin, Georgia, is a multistemmed, compact


Author: Harry B. Lagerstedt

PP: 91

The technique of grafting is over 2,000 years old, so it might be presumptuous to assume that something new can be added. Yet the wheel, which is thought to be over 5,000 years old, is continually being improved as new materials are developed. There can be no change in the basic design of the wheel, only in its size or the materials utilized. In the same way, there can be no change in the basic principles involved in grafting, only in the tools, materials, or methods used in preparing the grafts. It is the objective of this paper to review certain grafting techniques and to present some materials and methods which have improved nut tree grafting success. This will be done while considering the basic principles involved in grafting.

Author: J.C. McDaniel

PP: 377

Can you help us test some meritorious new ornamentals? We are planning to distribute to selected nursery propagators and some arboretums in early 1970, a few scions from two new hybrid magnolia cultivars originated here, and a self-fertile clone of M. acuminata, plus some other small flowering trees recently named, registered, and test propagated. I should like to hear from you soon if you are interested in initiating propagation of any one or more of the following items, none of which is patented.
  1. Magnolia ‘Ballerina’ is a Loebner magnolia, seedling of M. × loebneri ‘Spring Snow’, possibly crossed with M. stellata ‘Waterlily’. Of similar season to the well-known Loebner magnolia ‘Merrill’, this has considerably more double flowers (to 30 + petals), is slightly pink-blushed and more highly fragrant. Judged by its first twelve years growth, it apparently will mature as a smaller tree than ‘Merrill’, but larger than M. stellata. The 1969 tests showed a high percentage of strong rooting with May

Author: Ralph Shugert

PP: 381

The Question Box session convened at 7:40 p.m. in the East Ballroom. Mr. Ralph Shugert served as moderator.

MODERATOR SHUGERT: Good evening, Ladies and Gentlemen; we shall now call the Question Box Session to order. For the benefit of those attending this session for the first time we ask all to participate. In order to have proper identity, we are asking everyone to do two things; wait for the microphone, and please give your name so it can be entered in the Proceedings. This can be very enlightening and interesting segment of the program if everyone will cooperate and participate. Thank you.

Now for the first question. Dr. Tehrani, how does your method of rooting hardwood cuttings work for ornamental varieties of cherries and flowering crabs?

G. TEHRANI: It does not seem to work too well with varieties of cherries; and I do not work with apples, so I have not tried this.

JOERG LEISS: The same type of treatment as Dr. Tehrani mentioned has been used on the Malus understocks of the


Author: Manuel P. Cabrita

PP: 390

At the time Captan first came on the market I was having trouble rooting geranium cuttings. We lost about 70% of every batch of these cuttings with Black Leg. I decided to make the cuttings of geraniums, dip them into Captan and plant them directly into soil in 2½ inch pots. In 4½ weeks they were rooted right through the pots. We rooted 90% of the cuttings treated this way.

Later I decided to try it on some evergreen cuttings we were making. The ones we used were the following: Thuja occidentalis ‘Nigra’ T. O. ‘Fastigiata’ (syn., ‘Pyramidalis’) Juniperus horizontalis ‘Plumosa Compacta’, J. chinensis ‘Hetzii’, Taxus × media ‘Hicks’, T. × m. ‘Hatfield’, T. ‘Densiformis’ and Buxus ‘Newport Blue’.

In preparing the bench, I white-washed it then laid polyethylene on the bottom of the bench and put in 6 inches of washed cement sand. The bench was then leveled off with a 2 × 4, much as you would do to float-off cement. I don't do any pounding of the sand to firm it; I just stick the cuttings into it. The cuttings


Author: Choong Il Lee

PP: 391

Extremely poor rooting of cuttings of some clones of Rhododendron is one of the factors which decreases the production efficiency of rhododendron. Some endogenous rooting factors, other than auxin, which control rooting are believed to occur in easy-to-root cuttings of some genera, but to be present in a smaller amount or absent in the difficult-to-root ones (1,3,4,5,6). Hess (2) suggested that the presence of four root-promoting substances, named rooting cofactors, in extracts from stem tissues of the juvenile form of Hedera helix L. cuttings was responsible for its high rooting capacity. The rooting cofactors have also been found in other plants and were related to rooting ability (2,4,6). They have not previously been studied in Rhododendron.

Objective of this study was to determine the relationship between rooting cofactor or inhibitor level and the clonal and seasonal variation in rooting response of cuttings in three clones of rhododendron.


Author: Donald Copes

PP: 97

Early detection of incompatible stock-scion combinations has been a problem for many years. External symptoms of incompatibility may not become evident until 10 to 40 years after grafting (7). Delayed incompatibility losses impose a serious handicap to nurserymen and orchardists. Internal incompatibility symptoms which are diagnostic of the relative compatibility of the graft have proven accurate for peach, pear, and plums (4), apricots (5), pear (6), and for Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) (2,3). Unfortunately, internal detection requires destruction of the graft, a microscope, and some knowledge of microtechnique procedures. Obviously, nurserymen and orchardists would be better served by a simple visual test based exclusively on external appearance of the grafted plant.

Past attempts to find such a test have generally failed. Symptoms such as chlorosis, leaf drop, initiation of cambial activity, initiation of first-year bud elongation, amount of scion and stock


Author: Barrie D. Coate

PP: 102

Many important propagation procedures become so routine that we often relax our attention to them. I'm speaking of the day-to-day details of cleanliness in the propagation program. Disease organisms can and do travel all the way from the cutting bench, through the greenhouse into 1 and 5 gallon stock, as the diseased crop is transferred to larger containers. It is very difficult to convince some nurserymen that meticulous disease control in the propagation department is worth the man-hours it requires. However, consider the value of 25 5-gallon saleable plants lost to disease in a month as compared with one man-hour per day spent on cleaning propagating tables, floors, and equipment per month.
          25 5-gallon plants @ $3.00 ea. — $75.00
          25 hrs @ $2.50 per hr.            — $62.50

Even if only 25 5's per month are lost to disease, and this can be prevented, money would be saved. Another point in favor of good sanitation practices is the fact that chemical control over disease, once the disease is