From http://www.preservationtree.com/ in Dallas, TX
We know it can be tempting to take care of much needed tree pruning on your own. Often, we just hire the guy down the street that's "handy with a chainsaw". Who doesn't want to save some money? Problem is, poor "cheap" pruning can permanently ruin the look of your valuable trees and often leave them susceptible to storm damage, disease and ultimately decline and death. Here are five of our top common pruning and trimming mistakes we see on trees around the DFW area.
- Topping: This is usually one of the most obvious and ugly of tree pruning mistakes. It happens a lot with crapemyrtles (known as "crape murder") and other trees that were too large for the place they were planted. With crapemyrtles, it's also done because people think it will get them more blooms (it won't). Topping involves cutting away a large section of the top of a tree's crown, or all the leafing branches across the top half of the tree. What you're left with is a very ugly deformed specimen with severely weakend branch structure.
- Bad Timing: There are good times to prune and bad times to prune; it depends on the species and condition of the tree. In Texas, for example, oak trees should not be pruned from February through June, due to the spread of oak wilt disease. If a tree is already stressed, it should not be heavily pruned. You should always have your trees inspected by a certified arborist before you let anyone take a chainsaw to it, unless you're willing to lose the tree completely. Pruning west-facing branches isn't a good idea in the heat of the summer; when you remove large limbs that shade the tree from the hot western sun, you can cause sun scald on red oaks, maples and other susceptible species. Sun scald results in wounds and damage to the trunk bark that can severely damage your tree.
- Improper Cuts: A very common tree trimming mistake when removing branches is to cut them off too close, or flush, to the main trunk. By doing this, you remove the branch collar; an area of tissue with specialized cells that help heal the wound. You'll recognize it as a small swelling, or bump, right where the branch meets the trunk. The callous that the branch collar cells creates will prevent disease from entering the trunk. When you cut that branch off flush to the trunk, you're opening a wound that can allow in disease and pests, putting your tree on a path to an early demise. Bark tears can occur when the proper steps are not taken when removing large branches. If you make the wrong cut in the wrong order, you can end up with a large branch falling and tearing or splitting your main trunk.
- Over Pruning: No more than about 15% to 20% of a mature tree's foliage should ever be trimmed off at one time. In fact, 5%-10% is usually adequate. When you remove too much of the canopy, you'll leave the tree unable to produce enough food, transfer nutrients and structurally support itself. People often over trim and thin their trees in hopes of getting the grass beneath to grow properly (which rarely happens). If you have multiple trees in an area where you'd rather grow turn, often a better practice is to remove selected trees to let in more light, and perform structural pruning on the remaining trees so that you can have both healthy trees and turf.
- Raising the Canopy Too High: Otherwise known as Lion's tailing, or as we like to call them "Broccoli Trees". Again, unskilled labor often removes far too many large lower branches in an effort to raise the canopy and grow more turf grass. 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. You can read more about this pruning mistake and the problems it causes HERE.