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LIGHT:— ITS INFLUENCE ON VEGETATION. 



(Continued from page \\2.) 



The great desideratum in plant growing is to have a symmetrical 

 growth, green healthy foliage, and short-jointed wood, which, at the 

 proper season, should be well furnished with bloom. As this last con- 

 dition is the admitted criterion of excellence for exhibition plants, it 

 follows that a too luxuriant state of growth must not be encouraged 

 beyond a certain limit, as this would interfere with the full develop- 

 ment of bloom, the great object to attain in growing plants for display. 

 I need hardly remind your readers, that to know exactly how to regu- 

 late or control the growth of plants, so as to check further growth and 

 direct the energies of the plant towards the maturation of the wood, or 

 to induce that state of repose necessary to enable it to form the requisite 

 secretions for organising flower-buds, is one of the great triumphs of 

 the gardener's art, and only to be obtained by a practical acquaintance 

 with the peculiar habits of each race of plants ; the agent by which he 

 effects his purpose is light, in connexion with heat, due regard being 

 paid at the same time to the state of the roots. 



Supposing then a collection of ordinary hard-wooded greenhouse 

 plants are being started into growth in the spring, it should be the main 

 object of the manager to see that every plant is exposed to as much 

 light as can be made to reach it. This premises that the plants should 

 be as near the glass as possible, and sufficiently wide apart to allow the 

 light to" fall on every part of tlie plants, as well as fjr tlie air to circu- 

 late freely between them. As each shoot advances, it will be acted 

 upon by the agency we are considering, and as each leaf is formed it 

 will be enabled to perform its allotted functions in the |)lant's economy : 

 there will be no drawing, because each leaf, having the full exercise of 

 its powers, will therefore be enabled to build up and make strong the 

 young growth ; and as the general health of the plant will depend on 

 the healthy action of the leaves, we shall in time have plants possessing 

 all the properties which constitute their value as specimens, and which 

 we have pointed out at the commencement of this article, attention 

 having in the meantime been paid to supplying their roots with the 

 necessary elements for their growth. But as tlie time will arrive when 

 further growth should be gradually arrested, and when subjected to a 

 drier atmosphere a more complete exposure to light will be necessary, 

 to perfect the growth already made and allow time for the due formation 

 of the embryo flower-buds. 



In stating that plants are benefited — and, indeed, can only be grown 

 in perfection — when every leaf is brought under the influence of light, 

 I by no means wish it to be understood that in all cases full exposure 

 to the sun under glass sliould be permitted, being fully aware tliat, 

 under glass, the plants we are considering would suffer, not perhaps from 

 free exposure to light alone, if attended with complete ventilation, but 

 to the heating rays of the sun, which are injurious to many plants when 

 under glass, although not so when fully exposed out of doors. Shading, 



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