|My Rose of Sharon trees haven't bloomed very well the past few years. They have lots of leaves but they don't bloom. Trees are rather large about 10 ft tall. Would pruning them back quite a bit help in the blooming process?|
|Lack of bloom can be caused by several things, including too much nitrogen in whatever it is you fertilize them with. Nitrogen can cause a big green flush at the expense of the bloom. If you have it growing in or near your lawn, it could be that the lawn fertilizer, which is usually high in nitrogen, is feeding your Rose of Sharon.|
Your Rose of Sharon likes a pH of 7.5-8.4. Perhaps the addition of some limestone might help as well.
You can prune hibuscus in the late winter or very early spring. Cut out any winter damaged branches, and all branches that are diseased or out of shape. Then cut back all the remaining branches slightly as well. Hibiscus (which is what a Rose of Sharon really is) blooms on new wood. This should be a big help.