30 TREES AND SHRUBS 



Periploca. — A climbing genus which should be 

 thinned out in winter, and only shortened back if 

 necessary. 



Pernettya. — These should not be pruned at any 

 time. 



Philadelphus. — These should be thinned after 

 flowering, and the old wood cut back to strong 

 young shoots. This is especially important with 

 P. microphyllus, P. coronarius, and P. Lemoinei and its 

 varieties. 



Photinia. — Requires no pruning. 



Pieris. — Remove seed-pods. 



POTENTILLA. — Thin Out after flowering, and shorten 

 any old wood back to strong young breaks. 



Prunus. — When young, all the members of this 

 genus that are grafted or budded are improved by 

 being cut back each spring until they have attained 

 a fair size and shape. More especially is this the 

 case with the Almonds, double-flowered Peaches, and 

 the various flowering Cherries. When older, they 

 need only be thinned and the flowering Plums and 

 Cherries kept spurred in, but not too hard. Prunus 

 japonica, P. nana, and P. triloba should be cut down 

 to strong young breaks after flowering, the resulting 

 wood bearing better flowers than the old wood. If 

 any of these three latter are grown on a wall they 

 should be spurred back hard after blooming. 



Ptelea. — When young, trim these to form small 

 trees, and do not allow them to develop into ungainly 

 bushes. When older, they require an occasional 

 thinning. P- trifoliata var. aurea, a golden form 



