My Althea Plants Are Not Looking Good

Question

I planted several Althea plants this spring and I have noticed two problems: the leaves are turning yellow and some of the leaves have white sections that are now turning black. Shortly after we had planted the Althea, we experienced a frost that turned many of the leaves very crispy – indicating some frost burn. I am not sure if the plants have some disease or if they are getting too much water. We have had a lot of rain over the last couple of weeks and when it has not rained we have been watering the plants. What do you recommend. See uploaded photos.

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Answer 1

I think these two articles will help:
https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon/yellowing-rose-sharon-leaves.htm
https://www.gardeningknowhow.com/ornamental/shrubs/rose-of-sharon/rose-of-sharon-problems.htm