Unfortunately, here in the Pacific Northwest, this growth is continuously trying to be best buds with roofs, siding, and trim elements. While most of the time this forced friendship appears as moss or fungal growth, occasionally, it looks a little more permanent.
During an inspection in Anacortes, I found such an arrangement when I noted vegetative growth coming through exterior walls. In my report, I stated there was a possibility of underlying damage not visible without invasive inspection.
If you have questions or comments about siding issues or home inspections in general, tweet me (@AIHomeInspect).