190 



UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



bringing it back into a symmetrical form. It is, therefore, often 

 better to let the tree take care of itself in this way, unless, as we have 

 said, it is distorted by wind, rather than to try to balance it up by 

 pruning. In case it is attempted to bring young walnut trees into 

 symmetrical form by pruning, and likewise in forming the tops of top- 

 grafted trees which have a tendency to become very top-heavy, better 

 results seem often to be obtained by summer pruning while the trees 



FIG. 22. Santa Barbara Soft Shell seedling walnut grove in which the trees have never 



been pruned. 



are in full growth and foliage rather than by cutting off limbs during 

 the winter. In the latter case large, strong suckers are apt to come 

 out at every cut and the shape of the tree becomes even worse than 

 before. On the other hand, by cutting back the green shoots while 

 they are growing their growth is decidedly checked, while those of 

 other parts of the tree, being in an active condition, develop rapidly 

 and produce the effect desired. 



