Signs a Dead Tree Will Fall Soon

Crown Symptoms

• The condition of a tree's crown is a good indicator of its condition. Dead or dying trees may drop their leaves suddenly, or leaves may remain on the tree but become shriveled and brown. Needles on conifers often turn brown and fall off. Storm-damaged trees, such as those with broken crowns or dangling branches, are particularly hazardous and should be removed immediately.

Cracks or Divisions

• Cracks in the tree trunk indicate structural weakness. Deep, long vertical cracks or multiple cracks are signs that the tree may dangerously weak. Cracks between large branches and the trunk indicate the branch may soon fall. Trees with forked trunks or multiple trunks growing together are especially prone to breakage if the union between the trunks becomes weak. Divisions or cracks between multiple trunks indicate that part of the tree may split away and fall.

Decay

• Decayed wood is soft, porous and brittle, making trees weak and unstable. Decay results when decomposing organisms such as fungi enter the tree through wounds or breaks in the trunk, branches or roots. Live trees can wall off a wounded area to prevent the spread of infection. However, decay progresses quickly in dead trees because the sapwood is no longer able to resist infection. Indications of decaying wood include loss of bark and the presence of wood-boring insects or woodpeckers. Multiple tiny holes in the trunk or sawdust on the ground are telltale signs of wood-boring beetles.

Root Problems

• Often an invisible danger, damage to a tree’s root system can cause the tree to topple suddenly, especially when the ground has been softened by heavy rain. Tree roots are sometimes cut or damaged by mowers or heavy equipment, such as during road work, grading or construction projects. Roots may also be damaged by burrowing animals, insect infestations and wet, swampy conditions. Damage often leads to infection, decay and root rot. The presence of mushrooms around tree roots or on the base of the trunk indicates decayed wood.

Leaning

• Although not all leaning trees are dangerous, a leaning dead tree is an accident waiting to happen. As a dead tree becomes weaker, it often leans, especially if it is on a hill or slope. A leaning tree can easily fall, and on windy or rainy days the danger increases. Signs that a tree might fall include raised ground or exposed roots on one side of the tree, indicating the root system is giving way.