CHAPTER IX. 



ON FORCING. 



Of all flowers induced to blossom, amid the chills of winter, there is perhaps 

 none which excites so much interest as the Rose. And as this branch of culture 

 is now so generally practised, it seems to demand more than a passing notice. 



The art of forcing consists in accelerating the period of growth and flowering 

 of plants, by means of artificial heat. In practising it, we change their seasons, 

 inducing them to perform certain functions at other seasons than those at which 

 they naturally perform them. With Roses, spring and summer is the natural 

 period of growth, autumn the period of maturation, and winter that of repose. 

 But supposing we commence forcing at Christmas, our winter becomes their 

 spring, our spring their summer, our summer their autumn, and our autumn their 

 season of rest. Thus, in forcing, although we change all the seasons, we take 

 care not to annul any one of them., or we sacrifice the health of the plants ; and 

 these changes should be brought about gradually. The first year the plants are 

 forced they should be advanced steadily, and should, in no case, be brought to 

 flower earlier than the middle of March. 



In the construction of the forcing-house, every chance of increasing the quan_ 

 tity of light should be accepted, remembering that, in their artificial spring, the 

 plants will not have the advantage of so long or so powerful a sunlight as in the 

 natural one. 



A house has been built here recently, for the express purpose of growing Roses 

 in pots to bloom in the spring of the year. Measured from the inside, it is thirty 

 feet long, and seventeen feet wide. It has a span-roof, with a longer slope to 

 the south, glass ends, and upright sashes at both fronts. There is a stage in the 

 centre, surrounded by a walk ; and a tank, three feet wide, runs round the inside 

 walls. Over this tank the pots are plunged in sawdust, and a gentle bottom heat 

 is maintained. The top lights are movable, that air may be given as required ; 

 and it is intended to substitute canvas for glass in the summer season. The 

 house is heated by a Stephenson's cast-iron boiler. A pipe runs round the 

 inside, furnishing it with atmospheric heat, emptying itself into the tank above 

 mentioned, which re-conducts the water to the boiler. This house was built for 

 Pot-roses only; but if flowers are not wanted before March or April, we think 



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