First Pruning

• The first pruning should happen when the tree is planted. Remove broken and dead limbs, crossing branches and branches growing in toward the crown. This first pruning can be done at any time of the year. The first pruning helps the young tree form a strong, stable structure. If done correctly, you will reduce the amount of pruning you will have to do as the tree matures.
  
  

Winter and Early Spring

• Most trees should be pruned in late winter or early spring while the tree is still dormant. Oaks, fruit and nut trees, locusts, and other hardwoods are pruned at this time. Late winter or early spring pruning reduces the risk of fungal or insect pests colonizing the open pruning wound, makes pruning easier as the structure of the tree is not obscured by leaves, and pruning wounds and cuts heal faster.
  
  

Early Flowering Trees

• Early flowering trees, like magnolias and dogwoods, which bloom on wood grown the previous year, should be pruned when they stop blooming and the flowers have faded. If you prune while the tree is dormant you will decrease the amount of blooms your tree produces. Fruit trees bloom early in the year; however, they should be pruned in late winter as their blooms develop on new growth.
  
  

Maples and Other Sappy Trees

• Sappy trees, like maples, birches and beeches, should be pruned in late spring or early summer after their leaves have fully emerged. In late winter and early spring these trees start producing sap in preparation for the upcoming growing season. If pruned at this time, sap runs from the open wound down the tree trunk. You can prune while the tree is dormant, just apply a wound coating to the pruning cuts. If you don't, and allow the sap to run freely you will stress the tree, and the sap, even when dried, may attract insect pests.
  
  

Evergreens

• Evergreens can be pruned from late winter through mid-summer. Evergreens are trees that do not lose their leaves in fall or winter. Many evergreens are pruned into hedges and topiary. Hedges and topiary should be pruned in late spring, just as new growth emerges, and pruned again when new growth is 6 to 8 inches long. The only evergreens that should not be pruned are pines. Pines increase their size through growing tips at the end of branches. Once a growing tip is removed, the branch will not get any larger and a bare stub will form at the end.
  
  

Other Times to Prune

• The following pruning needs to occur regardless of the time of year: Always remove dead or dying branches. Remove branches that are threatening power lines or are growing too near buildings. Remove branches that are infested with insect pests like web worms.