264 CALIFORNIA FRUITS: HOW TO GROW THEM 



buds are well advanced or the tree in bloom. He has trees which 

 were over thirty years old before they were re-headed, and they 

 made fine tops of new and healthy wood, and produced abundantly. 

 The cherry is in fact a very easy tree to graft by the usual top- 

 grafting methods. 



PESTS AND DISEASES OF THE CHERRY 



The disease of the cherry which is most heard of is the "gum," 

 or overflow and condensation of sap, which, if left to itself, often 

 induces decay of adjacent bark and wood. Without attempting 

 to explain the cause or causes of the unhealthy exudation, it may 

 be said that prompt treatment of certain manifestations is desir- 

 able, and in others the tree should be cleansed from the flow. 

 Where the gum exudes on the side of trunk or limb, the thin 

 outer bark should be pared away with a sharp knife, the accumu- 

 lation of gum and sap removed, and the wound painted with lead 

 and oil paint, or covered with grafting wax. 



Gum in the crotch should be cleanly brushed out when soft- 

 ened by the winter rains. If allowed to remain, it becomes sour and 

 offensive and may injure the tree. In places where two or three 

 limbs come out close together a kind of cup is formed, which will 

 hold the gum from one year's end to another, and in its soft state, 

 leaves, sticks, cherry pits, dust, and dirt will stick and hang and 

 sometimes the mass becomes very foul. By this collection also, 

 a nest is made for all manner of insects, bugs and worms. Another 

 evil is letting the gum stay on is, if rain does not wash it off clean, 

 it runs down the trunk of the tree and makes the bark look bad, 

 and if it is very thick on the bark when it dries, it will contract 

 and crack the bark crosswise, and is very injurious to the tree. 



Gumming in the crotch can be largely avoided by starting 

 the young cherry as advocated in the chapter on pruning. 

 Branches which emerge from the trunk at separate points and at 

 wide angles seldom gum ; those which are crowded together or 

 emerge at acute angles gum badly. In shaping young trees a 

 gumming joint sometimes may be clearly cut out and those 

 branches selected to remain which start out at a wider angle ; in 

 older trees there is nothing to do but keep the fork clean, as already 

 described. 



There are cases reported in which gumming of old trees has 

 been stopped by allowing the ground to lie uncultivated, weeds 

 being cut down with the hoe. As a rule, however, the cherry thrives 

 with good cultivation. 



Die-back of the Cherry. The dying back of cherry branches is 

 more or less common in all regions, and the immediate cause thereof 

 is not known. It is apparently sometimes a root trouble, as is the 

 dying back of other fruit trees. This might have resulted from 



