Dying Rose of Sharon
We bought a house with an amazing ROS -- it was pruned into a large tree with a trunk a foot wide and branches extending over 15 feet wide. Gorgeous. It was very happy and bloomed extensively. Unfortunately I took it for granted and didn't fertilize it. Now three years later it is in great distress. Last summer several branches didn't leaf out and the bark on the trunk began to split in the hot sun. Sap flowed out, making it very popular for the butterflies and bees. I had an arborist look at it and he said that something must be killing it underground, maybe one of its roots had grown incorrectly and was choking off the other roots. He said the bark on the trunk was cracking because the limbs that didn't leaf out had failed to protect the trunk and it was getting sunburned. Another person said it was an old tree (maybe as old as 30 years old?) and ROS don't live that long.
This year at least half the branches are still budding out and I am determined not to give up on it. I have already fertilized it with an all purpose fertilizer -- is there some type that is best for ROS? What should I do if the trunk cracks again? Can I protect it from the sun by wrapping it?
Any suggestions would be welcome!