THE GARDEN.

New Zealand Mail, Issue 1194, 18 January 1895, Page 7

THE GARDEN.

LECTURE ON RAISING NEW CHRYSANTHEMUMS, In commencing (says the 6ardeners' Chronicle ), Mr Shea said that seedraising had given him great pleasure, and would give the same to others who pursued the work with determination, and upon scientific and definite methods, but at the outset it would be well to consider what one had to compete against, and not to ignore the fact that France and the greater part of the Continent, besides China, Japan , and the United States of America, in addition to the trade and other growers in our own country, were all doing the same thing, and thus one individual’s chance of raising anything that shall gain the world’s notice, as well as interest ourselves, was but small. In addition, whilst the climate of France and other counti'ies was just thatrequired for such a purpose, that of our, own country was distinctly against the endeavour, and a climate like that of sunny France had to be provided as nearly as possible in the houses here during December, January, and February. On the other hand, we gained indirectly in this country by being obliged to keep our plants inside, and, therefore they are not subjected to the visits of insets and such injurious agencies at work outside. To commence in a small way, a greenhouse would be wanted about 12ft. by Bft., and it must be built in such a manner that dripping and damp can be eliminated. Thepaths must be cemented, and on an incline, to ensue that all water pass quickly awa} r . Ventilators should be so arranged that the air has to pass over the hot-water pipes upon entering the house, and, indeed, every means that can be used to keep a warm, moving, dry atmosphere, should be adopted. In selecting plants as subjects to work from and upon, the seed raiser must not choose overgrown plants that have been cultivated for exhibition blooms A double flower is not required, as the essential organs are destroyed or impaired by excessive cultivation. The variety may be the best double possible, but a flower with, a more or less open centre is required. The construction of the flower was then described. Mr. Shea said that the greatest care was required that the pollen be conveyed to the stigma at exactly the same time the latter is in a ripe state to receive it. That w~as where, in the majority of cases, the mistake occurred. The organs appeared to be ready long before they are, and then the peculiar means nature has provided in the chrysanthemum and other plants was described, whereby self-fertilisation was rendered infrequent, Mr Shea saying that the anthers have opened, and the pollen is all scattered before the two lobes of the style have opened at all, so that if the stigma of one plant is fertilised it will almost be sure to be so by the pollen of another plant. The correct time, then, for effecting pollenisation must be known, and when both anthers and stigma are ready, the process of taking a camel’s-hair brush and touching the anthers of the plant to be used as the male parent, and conveying the pollen to the stigma of another plant wa3 a simple matter. It should be repeated each day for a week, and about noon was the most suitable time. The lecturer had never known in his experience a case so treated that had failed.

The next important question would be, how to ripen the seed, Aphis,

tlirips, and other insects, besides bad atmospheric conditions, were enemies that would have to be contended with, and in regard to the former the house must be fumigated just as often as the plants required it. When the seed has formed Mr Shea has found that the practice of some American raisers of cutting off the petals was not advisable in this climate. They would serve as a safety valve to carry off any excess of sap, arid they should be left until they are withered.and then removed, or they may harbour insects. In regard to raising double varieties, Mr Shea had found that’the seed from the circumference will produce the highest percentage, and seed from the centre, or near it, the greatest proportion of single varieties. The same phenomena occurred in the cross-fertilisation of the begonia. The lecturer had only three singles amongst liis seedlings this season by following such a method. The best means Mr Shea knew of determining when the seeds were ready to be taken away was by touching the disc with the fingers, in order to see if the seed would fall. The centres of the discs are cut out to avoid single varieties as soon as the heads are collected. Suggestions were then given as* to the selection of varieties for crossing, and Mr Shea said it was impossible not to keep the shows in view, and it was essential that flowers of large size should be raised. Midseason flowers would be most popular, and to obtain them he would cross a grand late variety with an early one of the same degree of excellence. The habit, constitution, and height of the plants must be taken into consideration, and beauty of the flowers must not be allowed to lead the hybridiser to use as a parent-plant onegrowing to anenormous height. Mr Shea instanced a variety that runs 13ft or more, and said he kept it until it reached lift, and then threw it away. Refinement in the blooms was also something to aim at. Large flowers of coarse types should be avoided, and in the matter of colour any that are washy should not be used as parents or sought after. To raise chrysanthemums from seed, a great deal of patience was required, and a certain amount of intelligence, but it would bring a large amount of pleasure and would lead the experimentor on to attempt the production of sports by artificial means, and before them all lay the goal which, if Mr Shea himself was not successful in reaching, he hoped others may—viz, the honour of raising a blue chrysanthemum !