To keep your peach tree healthy, you'll need to carefully observe any symptoms of disease, treat the disease and remove damaged limbs from your tree. Some disease can be managed entirely by careful pruning. While diseased limbs on peach trees can take many forms, they will always look markedly different from the healthy wood on the tree.
Check for small freckles on peach tree fruit and twigs that may indicate peach scab. In the second season, affected twigs turn reddish brown. Treat the tree with a fungicide and trim off affected twigs. Large limbs don't become afflicted with scab.
Note any blisters you find on the bark of your peach tree; these indicate a tree affected with gummosis. Blisters may ooze sap. As the disease worsens the tree will leak more gum or sap. Cut off limbs that display this oozing or blistering.
Check peach trees that have been damaged by frost or sun scald for cankers. Cankers leak amber-colored gum like gummosis-affected trees. The bark on a canker cracks and turns dark brown in color. Limbs that have cankers can be trimmed back to healthy growth.
Observe the tree's wood to see if any growth doesn't sway in the wind. Wood that remains still is dead. While not diseased, dead wood can begin to rot and spread disease to healthy limbs. Remove dead growth by cutting it off at the base.
Monitor any limbs that display different coloring or texture than the other limbs, since this may indicate disease. Prune any broken, wounded or damaged growth since it may develop disease if left on the tree.