414 MANUAL OF GARDENING 



Washing and scrubbing the trees. 



The washing of orchard trees is an old practice. It usually 

 results in making a tree more vigorous. One reason is that it 

 destroys insects and fungi that lodge underneath the bark; but 

 probably the chief reason is that it softens the bark and allows 

 the trunk to expand. It is possible, also, that the potash from 

 the soap or lye eventually passes into the ground and affords 

 some plant-food. Trees are ordinarily washed with soap suds or 

 with a lye solution. The material is usually applied with an 

 old broom or a stiff brush. The scrubbing of the tree is perhaps 

 nearly or quite as beneficial as the application of the wash itself. 



It is customary to wash trees late in spring or early in summer, 

 and again in the fall, with the idea that such washing destroys 

 the eggs and the young of borers. It no doubt will destroy 

 borers if they are just getting a start, but it will not keep away 

 the insects that lay the eggs, and will not destroy the borers that 

 have found their way beneath the bark. It is perhaps quite as 

 well to wash the trees very early in the spring, when they are 

 starting into growth. 



It is an old practice to wash trees with strong lye when they 

 are affected with the oyster-shell bark louse. The modern 

 method of treating these pests, however, is to spray with some 

 kerosene or oil compound when the young growth is starting, 

 for at that time the young insects are migrating to the new wood 

 and they are very easily destroyed (p. 204). 



The whitewashing of the trunks of trees tends also to relieve 

 them of insects and fungi ; and it is probable that in hot and dry 

 regions the white covering affords protection from climate. 



Gathering and keeping fruit (see p. 158). 



Nearly all fruits should be gathered as soon as they will read- 

 ily part from the stems on which they are borne. With many 

 perishable fruits the proper time for gathering will be deter- 



