Question
Newly planted rose of sharon bush; after 2 weeks began to notice yellowing leaves/drop and some with irregular dark spots (does not appear to be mold looks almost like a burn mark?.

Answer
Dear Janice, The most likely reason that you are having leaf drop on a newly planted shrub would be because you aren't watering enough.  In general, the rose of Sharon should be planted in full to mostly sun, in an area with good drainage and should be watered every other day for several weeks, or every three days at least.  It will take several months for it to become well established.  The burn marks are probably from being dried out, and I see it frequently on underwatered plants that are newly planted.  The only other possibility would be that you have some type of fungus on this shrub, and you could test this by spraying the plant with NEEM, which is an organic fungicide, insecticide, and miticide, and is great for home gardens.  Check the water first, because that is the most likely culprit.  I hope this information helps.  Write back if you have more problems.  Good luck, Melissa