The answer to 'why is my stone walkway mud' is that a stone walkway can become muddy due to poor drainage, compacted soil, or excessive moisture. Symptoms may include standing water, soft or squishy spots, and tracking mud into your home.
Common causes include an inadequate base layer, lack of proper grading or slope, and heavy foot traffic. Solutions may involve improving drainage, adding a gravel or sand base, and resetting the stones to create a more level surface.