When to Prune

• Azaleas set their buds in the summer.azalea bud image by hazel proudlove from Fotolia.com
  
  Azaleas bloom on old wood, meaning that the buds for the current season's flowers were formed the previous summer. With a few exceptions, azaleas should be pruned between the end of flowering and the beginning of July, to ensure that you have maximum buds for the next year's flower display.
  
  

Tools for Pruning

• Use pruners, not hedge clippers.loppers image by Edsweb from Fotolia.com
  
  Don't use hedge clippers to prune your azaleas. Doing so creates an outer shell of foliage that completely shades the inner branches, making them leafless and prone to disease. Use hand pruners and cut each stem individually, making the cuts at staggered heights to mimic the natural growth habit of the shrub. Unlike most shrubs, azaleas have dormant buds all along the stems, so it's not necessary to cut back to another branch. Sterilize the pruners between cuts by dipping the blades in alcohol or a solution of one part household bleach mixed with nine parts water.
  
  

Removing Damaged Branches

• Cut out broken, dead or diseased growth on azaleas whenever found, regardless of season. Always cut back to healthy wood. Brown flecks on the cut surface are signs of disease and you need to cut further back until you see only clear wood. It's especially important to sterilize your pruners between cuts when removing diseased branches.
  
  

Tall, Late Season Growth

• Sometimes azaleas put out a few long shoots in late summer or autumn that spoil the shape of the shrub. These late-season shoots neither bloom well nor branch properly the next season, so they're best removed whenever they appear. Trim off the branches below the foliage line so the cuts are hidden.
  
  

Renewing Shrubs

• If your azalea has totally outgrown its spot or if it's become leggy and bare on the bottom, it's time to do some renewal pruning. You have two options. The quicker but more drastic method is to cut the entire shrub down to 12 inches from the ground, shaping the branches so the shrub is gently rounded. This is best done in early spring so the plant has the maximum amount of time for new growth to harden off before winter, but at the very latest, cut the azalea back immediately after flowering. It may take several years for the shrub to recover fully.
  
  A gentler but more time-consuming approach is to stagger the renewal process over three years. Remove one-third of the oldest branches the first spring, then one-half of the remaining old branches the second spring and the rest the third spring. Flowering will be reduced but you'll still have a good display, and this method is less stressful for the plant.