How to Save a Split Limb of an Oak Tree

Split oak tree limbs occur with unfortunate frequency during high winds and lightning storms. Before determining how to save the split limb of an oak or any deciduous tree, it is important to assess the long-term potential damage to the whole tree if this is attempted.

Stage 1: Limb Splits

Assess the damage - how large is the limb?

  • If  it is a major limb or the leader, one of the main upward branches attached directly to the trunk, it definitely cannot be saved. Bacteria, rot and insects will be able to penetrate the primary oak trunk and kill the tree quickly.
  • If it is a large but secondary limb, attached to a major limb or leader, check how much bark has pulled away from the support limb due to the split.
  • If a large section of bark has been ripped away by pulling of the limb as it split, the limb cannot be saved. Unlike human skin, bark cannot reattach itself by a "knitting" process where old cells and new are linked together.
  • If it is new growth distant from the trunk, remove it. The tree will be able to generate a new limb at or near that location.

Stage 2: Assess the Tree's Overall Health - Will It Survive the Loss of this Limb?

  • Examine the tree's condition. How many other branches has it lost?
  • If it has lost most of its top branches and a leader, as well as the split limb, it will not produce enough new leaves to survive. The entire tree must be felled.
  • If it has a substantial crown of branches along with a leader, and the split branch is one not directly attached to the trunk, removal of that branch will probably save the tree.
  • Check how much bark was pulled away by the split branch. If the ripped bark patch is less than 1/4 the diameter of the whole branch, the wound left by removing the split branch will heal over with new bark in a few years.
  • Have a professional arborist make this assessment as quickly as possible following the limb split, to forestall infection and infestation of the main tree trunk with disease and pests.

Stage 3: Prepare to Remove the Split Branch

  • The location of the split branch on the tree will determine how it should be removed.
  • Cut sections of the split branch off first to prevent tearing of the bark on the support branch.
  • A split branch growing at a 45-degree or greater angle to the tree should be removed with a near-vertical cut, to minimize the exposed wound size.
  • A split branch that was growing upright or at a slender angle to the trunk should be removed with a sharply angled cut, to prevent water from building up in the wound.
  • An arborist can determine the precise cutting style to minimize damage and promote healing of the tree wound.

In summary, split branches cannot be saved. Reduce long-term harm to the tree by removing split branches as fast as possible.