Check what's happening at the base of the tree. Pay attention to the roots of the tree, searching for soft spots or decay.
- Look at the collar of the tree. The collar is where, on the soil surface, the trunk and roots meet. To search for decay, Pull back the grass or ground-cover. It's a sign of developing decay if bark is missing, falling off, or broken, or if cracks in the trunk are present.
- Check-in the trunk for deep, wide cracks. These demonstrate structural weakness in the tree and need careful assessment. Swelling of the trunk, or an overgrowth of one area of the bark, also implies advanced decay. Use a probe to measure the degree of decay.
- Pay close attention to the top of the tree, or the crown. Watch out from the ground for broken or dangling branches, trees with missing bark, and bare branches with no new growth of leaves or buds.