• Fungus on upper trunk

    Fungus on upper trunk

    When fungus grows where two trunks meet, there is usually weakness below the surface. This situation requires immediate professional attention.
  • Trunk cavity

    Trunk cavity

    The hole created by an old pruning cut like this one sometimes allows decay to enter the trunk. Even if the hole is small, the cavity could be big. This tree required an "aerial" inspection to find out.
  • Trunk splitting apart

    Trunk splitting apart

    This massive Southern red oak splits into two trunks at about 20 feet above the ground. The arrows point to a new crack where the two trunks meet. Scary!! This problem qualifies the tree for an emergency removal before it hits three houses!
  • Burl


    A burl is an abnormal groth usually found on the trunk. In general it doesn't hurt the tree or indicate weakness. Burls are often confused with mushroom activity.
  • Slime flux

    Slime flux

    Sometimes trees "bleed" something other than sap. Slime flux is a surface infection that is usually harmless. If the stain is extensive, call a Certified Arborist.
  • Lightning scar on hardwood

    Lightning scar on hardwood

    Sometimes a tree can recover from a lightning strike like this. Call a certified arborist immediately to assess it.
  • Lightning scar on pine

    Lightning scar on pine

    Lightning strikes on pine trees usually attract pine bark beetles, which will probably kill the tree if the strike didn't. Call a professional if you see a scar like this on your tree.
  • Fusiform canker

    Fusiform canker

    Fusiform canker is a common fungus on pine trees that, if deep enough, can cause them to break.
  • Pitch tubes

    Pitch tubes

    Pine trees try to drown attacking beetles with pitch tubes made of sap. Pitch tubes can be different colors (rose on left, amber on right). If you see these on your tree trunk, it usually means the attack is extensive and the tree needs to be removed.
  • Bulge


    This pine tree is trying to strengthen a weakened area with extra wood. If you see this on your pine tree, there will most likely be a fusiform canker on the other side.
  • Woodpecker damage

    Woodpecker damage

    These trees are showing the work of a pileated woodpecker (left) and a yellow-bellied sapsucker (right). The pileated woodpecker is going after insects in decayed or dead wood; this tree is probably hazardous, but if it's not within range of the house, it might be perfect wildlife habitat. The sapsucker is opening a drainage hole for sap in live wood; the tree is probably okay.

    Zone 3: The trunk

    The trunk holds up the tree and supports the massive weight of its branches. Inspect the trunk thoroughly.

    • Cavities can be dangerous, depending on their size, where they're located on the tree, and how deep they are. If there is a cavity above eye level, a "climbing" (aerial) inspection may be needed to find out how deep it is and if there is decay.
    • Cracks and splits in the trunk are extremely dangerous. If there is a crack or split in the trunk, the entire tree could fall or break apart at any time.
    • Missing bark (or areas where bark is falling off) usually signals a dead section. Look for places on the tree’s trunk where there is no bark, the bark is falling off, or the bark is discolored. Missing bark can also indicate a surface wound, infection, or a fungus attack.
    • When ants and beetles attack a tree, they leave very fine, light-colored sawdust (“frass”) that is easy to see. Ants cutting into decayed wood leave coarse shavings. Pine bark beetles attacking a pine tree leave “pitch tubes” that resemble marble-sized balls of light-colored sap.
    • A long streak of missing bark coming down the tree usually means the tree was struck by lightning. It's possible that a tree can recover from this, but if the leaves or needles turn brown after several weeks, the tree has died. Call a Certified Arborist immediately if lightning has struck a pine tree near the home. Pine bark beetles can smell oozing sap from miles away. Spraying the tree will help deter an attack, which will certainly kill the tree if the lightning didn't.
    • Trees with 2 or more trunks sometimes crack and split where the trunks connect. Strong connections appear as a “U” shape; weak connections resemble a tight “V” shape. Sometimes a tree adds layers of wood over the trunk connection to strengthen a crack. After a windstorm, look at the connection in the tree where the trunks meet. Use binoculars if the connection is high up. If there is a lightly colored line that contrasts to the natural dark bark color, you are probably looking at a fresh crack. The tree may be in the process of splitting apart. Consider this situation an emergency.

    If you see any of the above conditions in your tree, call a Certified Arborist immediately to determine if your tree is stable enough to leave standing or whether it should be removed.