Q. Any advice on Acacia trees would be great. These trees took a hit when the temps dropped to the 20's in December. I see new growth, but mostly on the suckers. Should I leave the suckers there or remove them? What is the best thing to do to help these trees recover?
A. This is more complicated. First you will remove any wood you know is dead. By now (June), any part of the tree which is still alive should have thrown out some growth. Remove any limbs that are dead (no growth coming from them) by cutting at point of attachment to another limb or the trunk. You should not leave any stubs when you are done.
If the limb is large and heavy, you should remove it by either removing sections of the limb at a time that are manageable or use a technique that we sometimes call the 1-2-3 method. This is demonstrated pretty good on Wikihow http://www.wikihow.com/Cut-a-Limb-from-a-Tree
Next, remove any broken branches. They will not repair themselves. Remove any wild or “sucker” growth. This type of growth usually has weak attachment to the trunk and not support itself in years to come. Remove any growth coming from the trunk that is not high enough in the future.
This growth will not get any higher and as it gets bigger will “sag” or bend downward perhaps into places where you can bang your head. Remove these by making a “flesh cut” in other words remove it all and don’t leave a stub.
Finally thin out the remaining branches so that any dead wood is removed (again by making “thinning cut” which is the same as in the third sentence, removing it at a point of attachment without leaving a stub.) Try to have the remaining branches going in different directions to help balance the crown visually.
I hope this helps. By the way, I would do any major limb removal next early spring after the worst temperatures have passed. Minor cuts (with a hand shears) can be done any time.