The answer to 'why is my retaining wall thin grass' is that there are a few common causes for thin or sparse grass growth along a retaining wall. This can be due to poor soil conditions, insufficient sunlight, or improper drainage. The thin grass may be a symptom of underlying issues with the retaining wall construction or the surrounding landscape.
One of the most common causes is that the soil along the retaining wall is poor quality, compacted, or lacks the necessary nutrients for healthy grass growth. The wall itself can also create a microclimate that is drier or receives less sunlight, making it difficult for grass to thrive. Additionally, if the wall was not properly graded or has drainage issues, water may not be able to properly soak into the soil, leading to dry, thin grass.