Lost in the trees: People's questions, expert's answers

Trees were the subject of questions asked at the Extension office in recent days. Here are some samples.
Q. My Italian cypress tree has a few dying branches on it. Could this be a disease? Also, is there a disease going around in leyland cypress trees? B.H., Lynchburg
A. Conditions in Virginia are not suitable for Italian cypresses. They prefer a Mediterranean climate and thrive in states like California and New Mexico. Leyland cypresses are being killed by seiridium canker all around the Southeast, and now the disease is starting to show up in Lynchburg. Mulching and watering are recommended to prevent seiridium canker.
Q. I have a crape myrtle that I planted two years ago. It was blooming when I purchased it, with nice large blooms. In the two years since, it has had no blooms. I had a crape myrtle in that spot previously (it was accidentally damaged with a chemical spray and died), and it bloomed profusely for years. So it seems the location should not be a problem. Any suggestions? R.W., Bedford
A. Four possibilities come to mind. Aphids could have fed on the tree’s buds and caused them to drop off. Powdery mildew could have killed the buds, too. Perhaps the tree is getting too much nitrogen fertilizer. The tree could also be putting its energy into developing a root system before it comes into full bloom. If that is the case, it should flower in a year or two.
Q. I hope that you may be able to give me some advice regarding a 100-year-old red oak tree that recently split and had the top broken out of it during a tornado that struck at my home on July 17. The tree was about 80-plus-feet tall, and it split during the storm. The tree itself is still standing about 20-feet tall. I am wondering if there is a possibility that I can save the tree, rather than cut it down, as everyone is telling me to do. If it were cut where it split with a power saw and then treated, does it stand a chance of surviving? This may seem like a stupid question, but I just really don’t want to cut the tree down unless I have to. It has provided shade for me and my family for almost 30 years now. Thank you for any advice you may be able to give me. T.C., Altavista
A. What is left of your tree will probably sprout new branches and continue growing next year. Unfortunately, it will never look anything like it once did. Decay has already begun to get started at the point where it split, and there is nothing you can do to stop it. A generation ago, the treatment would have involved painting the exposed wood with a tar-like wound dressing in the belief that it keeps out insects and disease. Wound dressings have since been proven to be of cosmetic value only.