- 6 - 

 Summer Pruning 



Interest in summer pruning has increased as orchardists have 

 experienced difficulties with excessive tree vigor in high density 

 plantings . 



Summer pruning of fruit trees means different practices to 

 different people. 



Some orchardists consider summer pruning to be nothing more 

 than removal of water sprouts, which are removed by hand or with 

 pruning equipment in mid-season. This pruning removes the vigor- 

 ous upright current season's shoots developing on the scaffolds 

 and interior of the tree, especially in the vicinity of large prun- 

 ing cuts that were made during dormant pruning. 



Some clonal rootstocks and some of the interstem trees tend 

 to grow numerous suckers from the rootstock. Orchardists who prune 

 these off during the summer often refer to the practice as summer 

 pruning. 



Occasionally, an orchardist will perform dormant season-type 

 pruning during the growing season. This involves moderate to 

 heavy pruning with selective branch removal, including heavy cuts. 

 Apple trees subjected to such pruning in June can be severely weak- 

 ened or stunted and fruit may fail to grow to optimum size. Flower- 

 bud initiation may be reduced and there is the possibility of tem- 

 porarily throwing the tree out of production. 



Summer hedging is the summer pruning concept of a few orchard- 

 ists, but it has presented some problems. Initially, summer hedg- 

 ing was done in mid-season after the initial flush of growth. Re- 

 growth occurred the same season in the vicinity of the pruning cuts 

 resulting in development of "crows feet" type growth on the tree's 

 periphery. Excessive shading in the tree's interior occurred. 

 When summer hedging is delayed, less regrowth occurs, thus the most 

 successful summer hedging of apples is normally performed in mid- 

 August. Follow-up dormant pruning is also necessary but this con- 

 sists of numerous fine cuts, thinning out the growth around the 

 periphery of the tree plus removal of large branches causing crowd- 

 ing. 



Summer pruning of young, vigorous, closely-planted apple trees 

 that are crowding has consisted of selective heading-back and selec- 

 tive removal of shoots to reduce tree vigor. Upright vigorous 

 shoots originating on the main scaffolds are removed. Cutting to 

 a lateral or to an apple is most dwarfing. Delaying this pruning 

 until August results in less difficulty with regrowth whereas if 

 performed in June or early July, regrowth beneath the cut usually 

 occurs, especially if pruning stubs remain. 



Summer pruning to control tree size of bearing trees can af- 

 fect shoot growth and flowerbud development. Shoots are usually 



