The answer to 'why is my hedge mud' is that your hedge is likely becoming overgrown and retaining too much moisture. This can happen when hedges are not properly maintained, leading to a thick, muddy appearance. Common causes include insufficient pruning, poor drainage, and heavy rainfall or watering.
The symptoms of a muddy hedge include a dense, matted appearance, with the leaves and branches becoming coated in mud. This can make the hedge look unattractive and unhealthy. If left untreated, the excess moisture can lead to fungal growth and other issues that can damage the plants.