254 ON TAKING IN GREENHOUSE PLANTS. 



heaths are of that unsociable nature, that they will not do well if 

 mixed promiscuously with other plants, especially any of the broad 

 leaved kinds : it is implied by this observation, tbat there should, if 

 possible, in all large collections at leasl, be separate houses for these 

 very numerous genera ; but in all houses there is a variety of 

 situations ; some more airy, near the windows, on end and front 

 benches, for such as heaths, Proteas, &c. ; all mountainous, Cape 

 plants, should be kept if possible on shelves, such as graphaliums, 

 bulbous geraniums, &c. &c. ; some closer, as the principal stage and 

 back benches, for orange trees, geraniums, and all such as grow in low- 

 sheltered situations: thus in every instance it is necessary to attend 

 to natural habit. 



When they are all housed, and dirt of every description taken 

 away, let as much free air be given as possible in the day time ; and 

 even at night, should the weather prove moderately mild, and free 

 from any appearance of frost. In fact, I have seldom seen frosts 

 at this early season so severe, as to injure any greenhouse plants, 

 that were not immediately exposed to its perpendicular effect : there- 

 fore the front windows may be kept open continually, unless there is 

 a prospect of its being particularly severe, or accompanied with cold 

 driving winds, in which case it will be necessary to keep them pretty 

 close. 



If air is too sparingly admitted at this season, when many of the 

 plants have not yet finished their summer's growth, it will inevitably 

 cause them to produce weak and tender shoots ; which will be ex- 

 tremely liable to damp off at a more advanced season, when the 

 house must be unavoidably kept close on account of the severities of 

 the external air; and besides, it will tend to give them amore general 

 tender habit, and render them less able to resist the winter colds 

 than they otherwise would. Hence it is evident, that they cannot 

 receive too much air, whenever the state of the external air will ad- 

 mit of it, by being free from all appearance of frost ; as it will be so 

 much to their advantage to be thus hardened, before the winter 

 assumes its severest front. 



This is a practise I would strenuously recommend to all cultivators 

 of exotics, to be observed the whole period they remain in the house, 

 their own observations on the state of the weather being their con- 

 stant guide. 



Water should also be plentifully administered when they are first 

 taken into the house, as the dry board, on which they now stand 

 as well as the elevated situation, and free circulating air, occasions 

 them to require more than when they stood on the moist earth; 



