I have a Rose of Sharon 3 years old 6 ft tall. 1/3 died after a later frost and even earlier spring growth spurt. The other half has odd growths on the branchs and has curling leaves. There is no yellowing of the leaves they are still a dark color. Growths are around the base of each leaf or where a leaf would be. Appears to be almost tumor-like in appearance. Any idea what this could be?