How and when to prune Dallas' trees

Before you prune your trees this winter, determine whether you should prune.

11:29 AM CST on Friday, January 25, 2008

By RICK ROSEN / The Dallas Morning News
rrosen@dallasnews.com

When pruning tree branches of 3 inches in diameter or less, make the first cut from the bottom, halfway into the branch and a few inches from the trunk or larger branch. Before you prune your trees this winter, determine whether you should prune.

Pruning can tame a tree that is outgrowing its location, and it can get rid of weak limbs that look as though they might fall. Pruning diseased limbs can prevent the disease from spreading. And pruning allows you to train the tree into a desired shape.

Done improperly, though, pruning can destroy the natural beauty of a tree. And heavy pruning can leave a tree weak, susceptible to disease or insect pests.

There is a difference between pruning and removing dead limbs. Deadwood can be removed at any time of the year, tree experts say. If you are not sure whether a limb is dead, scratch off a bit of bark with the blade of a hand pruner or your fingernail; living branches will be green underneath.

Winter is a good time to get rid of deadwood, because deciduous trees have dropped their leaves, allowing easy access to the limbs.

Because they are dormant, it also is a good time for pruning.
Make the second cut from the top, finishing the first cut made from the bottom. Before you start lopping off branches, step back and look at your tree. Visualize the shape you want it to be. (Of course, you should know what that particular tree's natural shape is.) And remember to prune with a light hand.

Here are pruning tips from Texas AgriLife Extension Service (formerly Texas Cooperative Extension):

•Start by removing dead, broken or diseased limbs. Cut them back from a lateral branch (a strong branch originating from the main trunk). This frequently opens up the canopy enough so no other pruning is needed.

•Eliminate weak or narrow crotches, where two branches connect. Angles less than 45 degrees are at risk of breaking. Another way to picture it: As you face your tree, look at it as a clock face; the 10 and the 2 are at about 45 degrees.

•If two main trunks are growing, consider cutting one off. A tree with one trunk generally is a stronger tree.

•When cutting off diseased limbs, disinfect blades between each cut with alcohol or heavily diluted bleach.

Garden maintenance checklist
• Make sure blades are sharp. Clean cuts encourage rapid healing.

•Pruning paint or other dressings are not necessary and may even slow down healing of the pruned area. The exception: on oak trees in areas where oak wilt disease is common.

•Use a three-part cut for big branches, those larger than 11/2 inches in diameter. First, saw under the branch, 6 to 12 inches out from the trunk; cut about one-third of the way through the branch. Second, cut through the branch at an angle from the top. Last, cut any stub back to the collar, which is a raised area that surrounds where two branches meet.

•Speaking of the collar, avoid causing a serious tree wound – don't cut large limbs flush with the trunk; always remove them at the collar.

One pruning practice to discard is "topping," in which trees are severely cut back. You see this particularly with crape myrtles. However, tree experts unite in discouraging the practice, believing it weakens the tree and ruins its shape.

And it's probably too early to trim fruit trees. The experts say to wait until late winter, just before bud break. Prune too early and a late freeze could cause severe damage. (The average date of the last freeze in our area is March 13.)

The best way to reduce the need for pruning is by placing the proper tree in the proper spot. If you know before you buy what the mature size of a tree will be, you'll be able to just sit and watch when your neighbors are pulling out their chainsaws.

PRUNING TOOLS

•Hand pruners can be used for twigs.

•Good lopping shears can cut limbs up to 2 inches.

•Saws are also helpful.

•Pole pruners let you reach high up.

•Other tools, particularly chainsaws, can be dangerous. Homeowners generally leave jobs that need chainsaws to professionals.