28 THE BOOK OF THE GREENHOUSE 



house plants and always a favourite. It should be 

 grown freely and well watered during summer as it 

 is subject to red spider if allowed to get at all dry, and 

 to keep this insect within bounds, the plants should be 

 well and frequently syringed. But little pruning should 

 be done when once the plants have assumed the required 

 shape ; all that is necessary in this way being to cut off 

 the flower heads when they pass out of bloom, as the 

 strongest and best shoots come from the upper portion 

 of the previous year's growth. 



Rhododendrons. — Greenhouse species of Rhododendron 

 afford very handsome plants, the treatment of which 

 nearly resembles that of the Azalea. Many of them 

 grow into big plants unsuited to the small house, but a 

 section that has been much developed during the past 

 decade or two is that of the Javanese. These are 

 slow growing plants which may be kept in rather 

 small pots and which flower more or less all the year 

 round. These Javanese forms require more than the 

 ordinary greenhouse heat and do best in the inter- 

 mediate house. Scarcely any pruning is necessary 

 further than to shorten a branch now and then for the 

 sake of symmetry. 



