120 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



of the stronger shoots when they have made about six inches of growth 

 and to keep the heads thinned. Pot trees naturally form half standards, 

 and the aim of pinching is to maintain an evenly balanced and fairly 

 compact head. Trellis trees should have their branches laid in about a 

 foot apart. With Oranges growth can be obtained anywhere from the old 

 wood by cutting back hard. 



In the fruiting-house at Sawbridgeworth two 4-inch pipes, a flow and 

 return, one above the other, run along each side, just inside the ventilators, 

 to warm the air as it comes in ; two others down the middle of either 

 border, let into the ground their own depth, give bottom heat without 

 drying out the soil. The path is down the centre, three feet wide, with a 

 border four feet wide on each side of it. This house, sixty feet long, 

 contains eighteen trees planted out and trained to the roof, and two 

 dozen pot trees. 



A crop of about five hundred or more excellent fruit may be expected, 

 although most of the pot trees are young and only carry very few. This 

 sounds rather paltry compared with what one hears of in South Africa : 

 single trees, about thirty feet high, from one of which you may gather a 

 thousand fruit and scarcely know that any have been picked ; nevertheless 

 it means a very good supply. 



The Oranges, being heavy, and usually borne at the tip of a slender 

 branch, require support ; this may easily be given by slinging the branch 

 to the wires in the case of trained trees, or to the main stem with pot trees. 



The house should run east and west to get the full benefit of the 

 winter sun. 



Oranges and Lemons need not necessarily be grown in a house by 

 themselves ; they may be put on the back wall of a plant-house and give 

 excellent results, provided the conditions described above are complied 

 with. One must be careful, however, to exclude all plants which, like the 

 Eucharis, are very susceptible to mealy bug. Conversely the Orange- 

 house may be used for plants ; the climate is very congenial to Ferns. 



Oranges have a bad name for being dirty trees and difficult to keep 

 clean. If allowed to get thoroughly dirty, no doubt it requires some 

 labour and patience to bring them round again ; this should never be 

 the case with a skilful cultivator. 



The sooty black layer, so often seen on the leaves of unclean trees, is 

 a fungus growing in the honeydew dropped on them by the various 

 scale insects which the trees harbour in quantity if allowed. 



Without insects the trees will keep clean automatically. 



Before the invention of fumigation by the evaporation of nicotine 

 compounds the process was not so easy. Tobacco paper was difficult to 

 regulate ; frequently it flared, and even without this, the hot smoke often 

 scorched the tips of the leaves if it did no worse. There is no excuse for 

 insects now one can fumigate all the year round, whenever necessary, with 

 no fear of bad results. 



If the trees are practically clean, but scale makes its appearance upon 

 a few isolated shoots, these should be washed or sprayed and the insects 

 destroyed thus without recourse to the fumigation of the whole house. 



The glass and woodwork should be thoroughly washed once a year. 



Three scale insects are the chief enemies of the Orange : the mealy 



