The answer to 'why is my shrub mud' is that your shrub may be experiencing poor drainage or soil compaction. This can cause the soil around the shrub to become saturated and muddy, especially after heavy rain or irrigation.
Common causes of muddy shrubs include heavy clay soil, soil compaction from foot traffic or equipment, and inadequate drainage. Symptoms include standing water, slow plant growth, and leaves that appear wilted or discolored. To fix the issue, you may need to improve soil drainage, aerate the soil, or even transplant the shrub to a better-draining location.