It depends on the problem, the affected part of the tree, the risk of the pathogen spreading, and the overall health of your tree. Many diseases, fungal infections, and insect infestations can be successfully treated, especially if the issue is only in a few branches. However, if a disease is too widespread, too severe, too easily spread, or in the roots, the tree will likely need to be removed.

You should not trim an oak tree in the summer. Oak trees are especially susceptible to disease, and open tree wounds are an invitation for beetles that carry tree-killing fungus. If there’s no risk that the oak tree will do damage to your property or hurt someone, it’s best to save the trimming for fall or winter. If you can, seal the wound with latex to prevent fungus from getting inside.

The best plan of action for an unhealthy or unsafe tree will depend on its condition. An arborist can recommend whether trimming or removal is the right call for your tree. Preventive tree trimming can keep trees safe and healthy, so make regular tree trimming a part of your yard maintenance plan.

Opt for a barefoot tree. Pros harvest barefoot trees when they’re dormant (leafless). They shake the dirt from the root ball and pack it in moist material. 

These trees can cost half as much as the trees at your local nursery, and you can buy them online—so there’s a much wider selection. Just make sure you keep your barefoot tree cool until you’re ready to plant it.