Rose of Sharon Tree

Mary Halfacer
by Mary Halfacer
How do I get my Rose of Sharon to open her buds? She grows really well, with branches, leaves and buds. But when it's time for the buds to open, they dry out. She is 4 years old. Last year I transplanted her to a high sun area thinking that might have been the problem.
All the trees around the area are already in full bloom. Mine is not. What is the problem?
This is the tree.
One of the buds.
Another bud.
  17 answers
  • First thing to check for~any bugs or weird fuzzy or sticky substance on the buds or leaves? If you do see this then mix some ivory or mild dish soap with water and give her leaves and buds a bath. Whenever I have a sick plant that is the first thing I check. I do not see any problems with the leaves in the pics as far as any fungus or mold so my next question is How much water is she getting? You should also make a slightly larger ring around her base and mulch it about 4" for moisture and weed control. Drought or lack of water can cause the buds to dry and fall off.
  • Douglas Hunt Douglas Hunt on Aug 14, 2013
    I think inadequate water is the most likely cause, although rose of Sharon can drop its flower buds for a frustrating number of reasons. Another possibility is a fungal disease called Botrytis that infects flower buds and causes them to turn brown and drop, often before or just after they open.
  • Peg Peg on Aug 14, 2013
    I agree with Doug and Renee. It look healthy to me, I don't see aphids or other pests on it, leaves look great too. I was going to suggest the same thing as Renee did as it was one of the first things I noticed - add a wider base around the tree and mulch. If you put any weed killer on the lawn, you don't want it close to the tree. And if they get dried out just one time, the plant will suffer and drop their buds. These look like they will be a "double" flowering type. I'd love to see it in bloom.
  • Catherine Smith Catherine Smith on Aug 14, 2013
    Agree with Doug and Renee as well. You might take a couple of those buds to your local extension agent. Botrytis can be controlled if it's caught early. RoS are tough, and that one looks very healthy.
  • Mary Halfacer Mary Halfacer on Aug 14, 2013
    Thank you for the suggestions. I do not believe it has bugs or a sticky substance. We have had a lot of rain this summer and we have been watering her. We will try the wider base and give it more water. Is there such a thing of too much water? We will also checked into the Botrytis disease. I've never heard of it. Thanks so much for the advice. I will get back to you.
  • Nancy Hand Nancy Hand on Aug 14, 2013
    Mary in the first picture the tree looks like it might be planted too deep, could it be??? I agree with all above check for Botrytis. :)
  • Mary Halfacer Mary Halfacer on Aug 15, 2013
    I don't believe the tree was planted too deep, but we are checking for Botrytis. Thanks Nancy.
    • Catherine Smith Catherine Smith on Aug 15, 2013
      @Mary Halfacer Agreed, it's not planted too deep. You wouldn't be getting bloom if that was the case. It very well may be from the "monsoons" we've been having, but please do check for the botrytis.
  • April E April E on Aug 16, 2013
    how often do you water it and for how long? do you use a sprinkler or a hose?
  • Janie Freeman Janie Freeman on Aug 16, 2013
    Why not try some Epsom salts or Phosphorus. I would try it some doses at first it suppose to encourage blossoms.
  • Mary Halfacer Mary Halfacer on Aug 16, 2013
    We have had a lot of rain in the Michigan area, so I haven't watered it much. How much water should it get?
  • Mary Halfacer Mary Halfacer on Aug 16, 2013
    How much Epsom salts? Do I mix it with water and what is the ratio?
  • Lauren Lauren on Aug 16, 2013
    You probably want to get a soil sample done too. This will help you know if the ph levels are right for the Rose of Sharon. It will also tell you what to add to your soil, if anything, to help the plant. You can get a soil sample kit from your extension services office. The store bought ones aren't always accurate.
  • April E April E on Aug 17, 2013
    most trees and shrubs need to be deep watered and having a lot of rain could be your issue if there is not adequate time for the soil to dry 4-5 inches deep you roots may not be getting the aeration needed and this could be causing the blooms to drop the first and most prevalent issue with plants are watering conditions and other when mother nature takes a hand they are the easiest to correct I would still think about a fungicide due to lots of rain means lots of moisture which is 1 of the things that leads to botrytis
  • Mary Halfacer Mary Halfacer on Aug 17, 2013
    Thank you April. My husband used a fungicide the other day and the blooms look like they about to open. I am keeping my fingers crossed and will let everyone know what happens.
  • Mary Halfacer Mary Halfacer on Aug 17, 2013
    Thanks Lauren. Wow so much good advice. I appreciate everything.
  • Peg Peg on Aug 19, 2013
    Hopefully you can post a pic of the flowers in bloom!!!!
  • Mary Halfacer Mary Halfacer on Aug 19, 2013
    I will shout from on top when my flowers bloom. Oh yes. Pictures will be posted when that happens.