172 PRACTICAL GARDENING. 



they grow in the dark, grows without thickening the stem, 

 and this evil is so completely one of degree, that ever}i;hing 

 grows weaker even in cloudy weather than it does in bright. 

 The necessity then of keeping down the temperature at night 

 must be obvious ; yet, in fifty out of sixty forcing-houses that 

 we have been in, the register has actually been higher at night 

 than it has been by dayhght. What is the consequence? 

 That all the forced plants and flowers brought into market are 

 weakly, and many could not, without unnatural supports, 

 maintain themselves in a sightly condition. This particular 

 point has never been half enforced in the treating of nurse- 

 ries, nor has it been well stated in the numerous publications 

 that profes? to guide us in the science of gardening. We, 

 therefore, repeat the lesson, that it may be well remembered. 

 We do not want plants in a forcing-house to grow in the dark, 

 because the stems grow longer without enlarging; and the 

 only way to prevent this is, to keep down the temperature at 

 night. In cloudy weather, too, it is desirable to keep the 

 house much cooler than in bright weather, because the evil is 

 felt in a less degree ; but still it is felt in the working of the 

 plants, flower stems, and general habit. Eoses are more forced 

 now than ever they were, from the fact of the societies giving 

 prizes for roses in pots in the May and June meetings ; but we 

 see many of them so ridiculously weak, that as many as twenty 

 or thirty sticks are necessarily employed to keep the branches 

 from dropping all over the pots. It would be well, therefore, 

 if people who have much to do with forcing would bear in 

 mind, that if they could altogether check the growth of a 

 plant by night, it would be well. Those who are in the habit 

 of shading theirs in bloom can testify that even this partial 

 abstraction of light draws the plant ; and as this is only when 

 the sun is out and very bright, unfortunately they cannot 

 keep down the temperature even if they would, except so far 

 as the shading keeps off the direct heat-rays of the sun. 



Some forcing-houses are constructed, or rather heated, on a 

 principle which makes one end warmer than the other ; but 

 those who lay themselves open to the forcing business should 

 have two houses, one like a greenhouse, the other warmed up 

 to the temperature necessary; aU things should go into the 

 greenhouse first for a few days, and then be taken into the 

 forcing-house. Eoses, which have always been considered 

 the most difficult, should be potted in the autumn, be placed 



