Raising the Canopy Too High: Otherwise known as Lion’s tailing.  Here, far too many large lower branches are removed in an effort to raise the canopy. What you end up with is a very tall bare trunk with a small amount of foliage canopy left at the top. It looks like a lion’s tail, or stalk of broccoli. 

The California Oak Foundation says, “excessive pruning or thinning of limbs may expose interior branches to sun damage, may stimulate the tree to produce succulent new growth that is subject to mildew, and, in some cases, may cause a decline in vigor or may kill an oak tree. Only dead, weakened, diseased, or dangerous branches should be removed.”