Time Frame

• Remove dead or diseased apple tree branches any time of year. Conduct structural pruning of trees from mid-November to mid-April when leaves aren't growing. Branches with diseases pruned away must be destroyed and pruners sterilized between cuts with a rinse of rubbing alcohol.
  
  

Considerations

• Washington State University Extension suggests thinning out, or pruning away, all tiny apple fruits in a cluster to leave only one fruit, by late spring. Space the remaining single developing apples every 4 to 6 inches along the branch length.
  
  

Expert Insight

• Gary Moulton and Jacky King, of the Mount Vernon Research and Extension Unit, suggest light pruning across the applet tree to maintain an upright, triangular structure of the canopy. Branch junctions angled between 45 and 60 degrees are strongest and bear the most fruit weight and wind loads.