The answer to 'tree trimming bare spots' is that common causes include excessive shade, soil compaction, drought, or improper mowing. Symptoms include thinning grass, exposed soil, and lack of growth. Solutions may include selective tree trimming, aerating the soil, improving irrigation, and overseeding the bare areas.
In general, minor bare spots can often be addressed through DIY methods like overseeding and soil amendments. However, for larger bare areas or issues with the tree itself, it's best to consult a professional arborist or landscaper to properly diagnose and treat the problem.